Merge tag 'regmap-v5.11' of git://git./linux/kernel/git/broonie/regmap

Pull regmap updates from Mark Brown:
 "This is quite a busy release for regmap with two substantial features
  being added:

    - Support for register maps Soundwire 1.2 multi-byte operations,
      allowing atomic support for registers larger than a single byte.

    - Support for relaxed I/O without barriers in MMIO regmaps, allowing
      them to be used efficiently on systems where default MMIO
      operations include barriers.

  There was also an addition and revert of use of the new Soundwire
  support for RT715 due to build issues with the driver built in, my
  tests only covered building it as a module, the patch wasn't just
  dropped as it had already been merged elsewhere"

* tag 'regmap-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  ASoC: rt715: Fix build
  regmap: sdw: add required header files
  regmap: Remove duplicate `type` field from regmap `regcache_sync` trace event
  regmap: Fix order of regmap write log
  regmap: mmio: add config option to allow relaxed MMIO accesses

Merge tag 'irq-core-2020-12-15' of git://git./linux/kernel/git/tip/tip

Pull irq updates from Thomas Gleixner:
 "Generic interrupt and irqchips subsystem updates. Unusually, there is
  not a single completely new irq chip driver, just new DT bindings and
  extensions of existing drivers to accomodate new variants!

  Core:

   - Consolidation and robustness changes for irq time accounting

   - Cleanup and consolidation of irq stats

   - Remove the fasteoi IPI flow which has been proved useless

   - Provide an interface for converting legacy interrupt mechanism into
     irqdomains

  Drivers:

   - Preliminary support for managed interrupts on platform devices

   - Correctly identify allocation of MSIs proxyied by another device

   - Generalise the Ocelot support to new SoCs

   - Improve GICv4.1 vcpu entry, matching the corresponding KVM
     optimisation

   - Work around spurious interrupts on Qualcomm PDC

   - Random fixes and cleanups"

* tag 'irq-core-2020-12-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
  irqchip/qcom-pdc: Fix phantom irq when changing between rising/falling
  driver core: platform: Add devm_platform_get_irqs_affinity()
  ACPI: Drop acpi_dev_irqresource_disabled()
  resource: Add irqresource_disabled()
  genirq/affinity: Add irq_update_affinity_desc()
  irqchip/gic-v3-its: Flag device allocation as proxied if behind a PCI bridge
  irqchip/gic-v3-its: Tag ITS device as shared if allocating for a proxy device
  platform-msi: Track shared domain allocation
  irqchip/ti-sci-intr: Fix freeing of irqs
  irqchip/ti-sci-inta: Fix printing of inta id on probe success
  drivers/irqchip: Remove EZChip NPS interrupt controller
  Revert "genirq: Add fasteoi IPI flow"
  irqchip/hip04: Make IPIs use handle_percpu_devid_irq()
  irqchip/bcm2836: Make IPIs use handle_percpu_devid_irq()
  irqchip/armada-370-xp: Make IPIs use handle_percpu_devid_irq()
  irqchip/gic, gic-v3: Make SGIs use handle_percpu_devid_irq()
  irqchip/ocelot: Add support for Jaguar2 platforms
  irqchip/ocelot: Add support for Serval platforms
  irqchip/ocelot: Add support for Luton platforms
  irqchip/ocelot: prepare to support more SoC
  ...

Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "More MM work: a memcg scalability improvememt"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm/lru: revise the comments of lru_lock
  mm/lru: introduce relock_page_lruvec()
  mm/lru: replace pgdat lru_lock with lruvec lock
  mm/swap.c: serialize memcg changes in pagevec_lru_move_fn
  mm/compaction: do page isolation first in compaction
  mm/lru: introduce TestClearPageLRU()
  mm/mlock: remove __munlock_isolate_lru_page()
  mm/mlock: remove lru_lock on TestClearPageMlocked
  mm/vmscan: remove lruvec reget in move_pages_to_lru
  mm/lru: move lock into lru_note_cost
  mm/swap.c: fold vm event PGROTATED into pagevec_move_tail_fn
  mm/memcg: add debug checking in lock_page_memcg
  mm: page_idle_get_page() does not need lru_lock
  mm/rmap: stop store reordering issue on page->mapping
  mm/vmscan: remove unnecessary lruvec adding
  mm/thp: narrow lru locking
  mm/thp: simplify lru_add_page_tail()
  mm/thp: use head for head page in lru_add_page_tail()
  mm/thp: move lru_add_page_tail() to huge_memory.c

mm/lru: revise the comments of lru_lock

Since we changed the pgdat->lru_lock to lruvec->lru_lock, it's time to fix
the incorrect comments in code.  Also fixed some zone->lru_lock comment
error from ancient time.  etc.

I struggled to understand the comment above move_pages_to_lru() (surely
it never calls page_referenced()), and eventually realized that most of
it had got separated from shrink_active_list(): move that comment back.

Link: https://lkml.kernel.org/r/1604566549-62481-20-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Jann Horn <jannh@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/lru: introduce relock_page_lruvec()

Add relock_page_lruvec() to replace repeated same code, no functional
change.

When testing for relock we can avoid the need for RCU locking if we simply
compare the page pgdat and memcg pointers versus those that the lruvec is
holding.  By doing this we can avoid the extra pointer walks and accesses
of the memory cgroup.

In addition we can avoid the checks entirely if lruvec is currently NULL.

[alex.shi@linux.alibaba.com: use page_memcg()]
Link: https://lkml.kernel.org/r/66d8e79d-7ec6-bfbc-1c82-bf32db3ae5b7@linux.alibaba.com
Link: https://lkml.kernel.org/r/1604566549-62481-19-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/lru: replace pgdat lru_lock with lruvec lock

This patch moves per node lru_lock into lruvec, thus bring a lru_lock for
each of memcg per node.  So on a large machine, each of memcg don't have
to suffer from per node pgdat->lru_lock competition.  They could go fast
with their self lru_lock.

After move memcg charge before lru inserting, page isolation could
serialize page's memcg, then per memcg lruvec lock is stable and could
replace per node lru lock.

In isolate_migratepages_block(), compact_unlock_should_abort and
lock_page_lruvec_irqsave are open coded to work with compact_control.
Also add a debug func in locking which may give some clues if there are
sth out of hands.

Daniel Jordan's testing show 62% improvement on modified readtwice case on
his 2P * 10 core * 2 HT broadwell box.
https://lore.kernel.org/lkml/20200915165807.kpp7uhiw7l3loofu@ca-dmjordan1.us.oracle.com/

Hugh Dickins helped on the patch polish, thanks!

[alex.shi@linux.alibaba.com: fix comment typo]
Link: https://lkml.kernel.org/r/5b085715-292a-4b43-50b3-d73dc90d1de5@linux.alibaba.com
[alex.shi@linux.alibaba.com: use page_memcg()]
Link: https://lkml.kernel.org/r/5a4c2b72-7ee8-2478-fc0e-85eb83aafec4@linux.alibaba.com
Link: https://lkml.kernel.org/r/1604566549-62481-18-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rong Chen <rong.a.chen@intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/swap.c: serialize memcg changes in pagevec_lru_move_fn

Hugh Dickins' found a memcg change bug on original version: If we want to
change the pgdat->lru_lock to memcg's lruvec lock, we have to serialize
mem_cgroup_move_account during pagevec_lru_move_fn.  The possible bad
scenario would like:

cpu 0 cpu 1
lruvec = mem_cgroup_page_lruvec()
if (!isolate_lru_page())
mem_cgroup_move_account

spin_lock_irqsave(&lruvec->lru_lock <== wrong lock.

So we need TestClearPageLRU to block isolate_lru_page(), that serializes
the memcg change.  and then removing the PageLRU check in move_fn callee
as the consequence.

__pagevec_lru_add_fn() is different from the others, because the pages it
deals with are, by definition, not yet on the lru.  TestClearPageLRU is
not needed and would not work, so __pagevec_lru_add() goes its own way.

Link: https://lkml.kernel.org/r/1604566549-62481-17-git-send-email-alex.shi@linux.alibaba.com
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/compaction: do page isolation first in compaction

Currently, compaction would get the lru_lock and then do page isolation
which works fine with pgdat->lru_lock, since any page isoltion would
compete for the lru_lock.  If we want to change to memcg lru_lock, we have
to isolate the page before getting lru_lock, thus isoltion would block
page's memcg change which relay on page isoltion too.  Then we could
safely use per memcg lru_lock later.

The new page isolation use previous introduced TestClearPageLRU() + pgdat
lru locking which will be changed to memcg lru lock later.

Hugh Dickins <hughd@google.com> fixed following bugs in this patch's early
version:

Fix lots of crashes under compaction load: isolate_migratepages_block()
must clean up appropriately when rejecting a page, setting PageLRU again
if it had been cleared; and a put_page() after get_page_unless_zero()
cannot safely be done while holding locked_lruvec - it may turn out to be
the final put_page(), which will take an lruvec lock when PageLRU.

And move __isolate_lru_page_prepare back after get_page_unless_zero to
make trylock_page() safe: trylock_page() is not safe to use at this time:
its setting PG_locked can race with the page being freed or allocated
("Bad page"), and can also erase flags being set by one of those "sole
owners" of a freshly allocated page who use non-atomic __SetPageFlag().

Link: https://lkml.kernel.org/r/1604566549-62481-16-git-send-email-alex.shi@linux.alibaba.com
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/lru: introduce TestClearPageLRU()

Currently lru_lock still guards both lru list and page's lru bit, that's
ok.  but if we want to use specific lruvec lock on the page, we need to
pin down the page's lruvec/memcg during locking.  Just taking lruvec lock
first may be undermined by the page's memcg charge/migration.  To fix this
problem, we will clear the lru bit out of locking and use it as pin down
action to block the page isolation in memcg changing.

So now a standard steps of page isolation is following:
1, get_page();         #pin the page avoid to be free
2, TestClearPageLRU(); #block other isolation like memcg change
3, spin_lock on lru_lock; #serialize lru list access
4, delete page from lru list;

This patch start with the first part: TestClearPageLRU, which combines
PageLRU check and ClearPageLRU into a macro func TestClearPageLRU.  This
function will be used as page isolation precondition to prevent other
isolations some where else.  Then there are may !PageLRU page on lru list,
need to remove BUG() checking accordingly.

There 2 rules for lru bit now:
1, the lru bit still indicate if a page on lru list, just in some
   temporary moment(isolating), the page may have no lru bit when
   it's on lru list.  but the page still must be on lru list when the
   lru bit set.
2, have to remove lru bit before delete it from lru list.

As Andrew Morton mentioned this change would dirty cacheline for a page
which isn't on the LRU.  But the loss would be acceptable in Rong Chen
<rong.a.chen@intel.com> report:
https://lore.kernel.org/lkml/20200304090301.GB5972@shao2-debian/

Link: https://lkml.kernel.org/r/1604566549-62481-15-git-send-email-alex.shi@linux.alibaba.com
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mlock: remove __munlock_isolate_lru_page()

__munlock_isolate_lru_page() only has one caller, remove it to clean up
and simplify code.

Link: https://lkml.kernel.org/r/1604566549-62481-14-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mlock: remove lru_lock on TestClearPageMlocked

In the func munlock_vma_page, comments mentained lru_lock needed for
serialization with split_huge_pages.  But the page must be PageLocked as
well as pages in split_huge_page series funcs.  Thus the PageLocked is
enough to serialize both funcs.

Further more, Hugh Dickins pointed: before splitting in
split_huge_page_to_list, the page was unmap_page() to remove pmd/ptes
which protect the page from munlock.  Thus, no needs to guard
__split_huge_page_tail for mlock clean, just keep the lru_lock there for
isolation purpose.

LKP found a preempt issue on __mod_zone_page_state which need change to
mod_zone_page_state.  Thanks!

Link: https://lkml.kernel.org/r/1604566549-62481-13-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan: remove lruvec reget in move_pages_to_lru

Isolated page shouldn't be recharged by memcg since the memcg migration
isn't possible at the time.  All pages were isolated from the same lruvec
(and isolation inhibits memcg migration).  So remove unnecessary
regetting.

Thanks to Alexander Duyck for pointing this out.

Link: https://lkml.kernel.org/r/1604566549-62481-12-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/lru: move lock into lru_note_cost

We have to move lru_lock into lru_note_cost, since it cycle up on memcg
tree, for future per lruvec lru_lock replace.  It's a bit ugly and may
cost a bit more locking, but benefit from multiple memcg locking could
cover the lost.

Link: https://lkml.kernel.org/r/1604566549-62481-11-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/swap.c: fold vm event PGROTATED into pagevec_move_tail_fn

Fold the PGROTATED event collection into pagevec_move_tail_fn call back
func like other funcs does in pagevec_lru_move_fn.  Thus we could save
func call pagevec_move_tail().  Now all usage of pagevec_lru_move_fn are
same and no needs of its 3rd parameter.

It's just simply the calling. No functional change.

[lkp@intel.com: found a build issue in the original patch, thanks]

Link: https://lkml.kernel.org/r/1604566549-62481-10-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memcg: add debug checking in lock_page_memcg

Add a debug checking in lock_page_memcg, then we could get alarm if
anything wrong here.

Link: https://lkml.kernel.org/r/1604566549-62481-9-git-send-email-alex.shi@linux.alibaba.com
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: page_idle_get_page() does not need lru_lock

It is necessary for page_idle_get_page() to recheck PageLRU() after
get_page_unless_zero(), but holding lru_lock around that serves no
useful purpose, and adds to lru_lock contention: delete it.

See https://lore.kernel.org/lkml/20150504031722.GA2768@blaptop for the
discussion that led to lru_lock there; but __page_set_anon_rmap() now uses
WRITE_ONCE(), and I see no other risk in page_idle_clear_pte_refs() using
rmap_walk() (beyond the risk of racing PageAnon->PageKsm, mostly but not
entirely prevented by page_count() check in ksm.c's write_protect_page():
that risk being shared with page_referenced() and not helped by lru_lock).

Link: https://lkml.kernel.org/r/1604566549-62481-8-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/rmap: stop store reordering issue on page->mapping

Hugh Dickins and Minchan Kim observed a long time issue which discussed
here, but actully the mentioned fix in

  https://lore.kernel.org/lkml/20150504031722.GA2768@blaptop/

was missed.

The store reordering may cause problem in the scenario:

CPU 0 CPU1
   do_anonymous_page
page_add_new_anon_rmap()
  page->mapping = anon_vma + PAGE_MAPPING_ANON
lru_cache_add_inactive_or_unevictable()
  spin_lock(lruvec->lock)
  SetPageLRU()
  spin_unlock(lruvec->lock)
/* idletacking judged it as LRU
 * page so pass the page in
 * page_idle_clear_pte_refs
 */
page_idle_clear_pte_refs
  rmap_walk
    if PageAnon(page)

Johannes give detailed examples how the store reordering could cause
trouble: "The concern is the SetPageLRU may get reorder before
'page->mapping' setting, That would make CPU 1 will observe at
page->mapping after observing PageLRU set on the page.

1. anon_vma + PAGE_MAPPING_ANON

   That's the in-order scenario and is fine.

2. NULL

   That's possible if the page->mapping store gets reordered to occur
   after SetPageLRU. That's fine too because we check for it.

3. anon_vma without the PAGE_MAPPING_ANON bit

   That would be a problem and could lead to all kinds of undesirable
   behavior including crashes and data corruption.

   Is it possible? AFAICT the compiler is allowed to tear the store to
   page->mapping and I don't see anything that would prevent it.

That said, I also don't see how the reader testing PageLRU under the
lru_lock would prevent that in the first place.  AFAICT we need that
WRITE_ONCE() around the page->mapping assignment."

[alex.shi@linux.alibaba.com: updated for comments change from Johannes]
Link: https://lkml.kernel.org/r/e66ef2e5-c74c-6498-e8b3-56c37b9d2d15@linux.alibaba.com
Link: https://lkml.kernel.org/r/1604566549-62481-7-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan: remove unnecessary lruvec adding

We don't have to add a freeable page into lru and then remove from it.
This change saves a couple of actions and makes the moving more clear.

The SetPageLRU needs to be kept before put_page_testzero for list
integrity, otherwise:

  #0 move_pages_to_lru             #1 release_pages
  if !put_page_testzero
                 if (put_page_testzero())
                    !PageLRU //skip lru_lock
     SetPageLRU()
     list_add(&page->lru,)
                                         list_add(&page->lru,)

[akpm@linux-foundation.org: coding style fixes]

Link: https://lkml.kernel.org/r/1604566549-62481-6-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/thp: narrow lru locking

lru_lock and page cache xa_lock have no obvious reason to be taken one
way round or the other: until now, lru_lock has been taken before page
cache xa_lock, when splitting a THP; but nothing else takes them
together.  Reverse that ordering: let's narrow the lru locking - but
leave local_irq_disable to block interrupts throughout, like before.

Hugh Dickins point: split_huge_page_to_list() was already silly, to be
using the _irqsave variant: it's just been taking sleeping locks, so
would already be broken if entered with interrupts enabled.  So we can
save passing flags argument down to __split_huge_page().

Why change the lock ordering here? That was hard to decide.  One reason:
when this series reaches per-memcg lru locking, it relies on the THP's
memcg to be stable when taking the lru_lock: that is now done after the
THP's refcount has been frozen, which ensures page memcg cannot change.

Another reason: previously, lock_page_memcg()'s move_lock was presumed
to nest inside lru_lock; but now lru_lock must nest inside (page cache
lock inside) move_lock, so it becomes possible to use lock_page_memcg()
to stabilize page memcg before taking its lru_lock.  That is not the
mechanism used in this series, but it is an option we want to keep open.

[hughd@google.com: rewrite commit log]

Link: https://lkml.kernel.org/r/1604566549-62481-5-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/thp: simplify lru_add_page_tail()

Simplify lru_add_page_tail(), there are actually only two cases
possible: split_huge_page_to_list(), with list supplied and head
isolated from lru by its caller; or split_huge_page(), with NULL list
and head on lru - because when head is racily isolated from lru, the
isolator's reference will stop the split from getting any further than
its page_ref_freeze().

So decide between the two cases by "list", but add VM_WARN_ON()s to
verify that they match our lru expectations.

[Hugh Dickins: rewrite commit log]

Link: https://lkml.kernel.org/r/1604566549-62481-4-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/thp: use head for head page in lru_add_page_tail()

Since the first parameter is only used by head page, it's better to make
it explicit.

Link: https://lkml.kernel.org/r/1604566549-62481-3-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/thp: move lru_add_page_tail() to huge_memory.c

Patch series "per memcg lru lock", v21.

This patchset includes 3 parts:

 1) some code cleanup and minimum optimization as preparation

 2) use TestCleanPageLRU as page isolation's precondition

 3) replace per node lru_lock with per memcg per node lru_lock

Current lru_lock is one for each of node, pgdat->lru_lock, that guard
for lru lists, but now we had moved the lru lists into memcg for long
time.  Still using per node lru_lock is clearly unscalable, pages on
each of memcgs have to compete each others for a whole lru_lock.  This
patchset try to use per lruvec/memcg lru_lock to repleace per node lru
lock to guard lru lists, make it scalable for memcgs and get performance
gain.

Currently lru_lock still guards both lru list and page's lru bit, that's
ok.  but if we want to use specific lruvec lock on the page, we need to
pin down the page's lruvec/memcg during locking.  Just taking lruvec
lock first may be undermined by the page's memcg charge/migration.  To
fix this problem, we could take out the page's lru bit clear and use it
as pin down action to block the memcg changes.  That's the reason for
new atomic func TestClearPageLRU.  So now isolating a page need both
actions: TestClearPageLRU and hold the lru_lock.

The typical usage of this is isolate_migratepages_block() in
compaction.c we have to take lru bit before lru lock, that serialized
the page isolation in memcg page charge/migration which will change
page's lruvec and new lru_lock in it.

The above solution suggested by Johannes Weiner, and based on his new
memcg charge path, then have this patchset.  (Hugh Dickins tested and
contributed much code from compaction fix to general code polish, thanks
a lot!).

Daniel Jordan's testing show 62% improvement on modified readtwice case
on his 2P * 10 core * 2 HT broadwell box on v18, which has no much
different with this v20.

 https://lore.kernel.org/lkml/20200915165807.kpp7uhiw7l3loofu@ca-dmjordan1.us.oracle.com/

Thanks to Hugh Dickins and Konstantin Khlebnikov, they both brought this
idea 8 years ago, and others who gave comments as well: Daniel Jordan,
Mel Gorman, Shakeel Butt, Matthew Wilcox, Alexander Duyck etc.

Thanks for Testing support from Intel 0day and Rong Chen, Fengguang Wu,
and Yun Wang.  Hugh Dickins also shared his kbuild-swap case.

This patch (of 19):

lru_add_page_tail() is only used in huge_memory.c, defining it in other
file with a CONFIG_TRANSPARENT_HUGEPAGE macro restrict just looks weird.

Let's move it THP. And make it static as Hugh Dickins suggested.

Link: https://lkml.kernel.org/r/1604566549-62481-1-git-send-email-alex.shi@linux.alibaba.com
Link: https://lkml.kernel.org/r/1604566549-62481-2-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: "Chen, Rong A" <rong.a.chen@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'staging-5.11-rc1' of git://git./linux/kernel/git/gregkh/staging

Pull staging / IIO driver updates from Greg KH:
 "Here is the big staging and IIO driver pull request for 5.11-rc1

  Lots of different things in here:

   - loads of driver updates

   - so many coding style cleanups

   - new IIO drivers

   - Android ION code is finally removed from the tree

   - wimax drivers are moved to staging on their way out of the kernel

  Nothing really exciting, just the constant grind of kernel development :)

  All have been in linux-next for a while with no reported issues"

* tag 'staging-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (341 commits)
  staging: olpc_dcon: Do not call platform_device_unregister() in dcon_probe()
  staging: most: Fix spelling mistake "tranceiver" -> "transceiver"
  staging: qlge: remove duplicate word in comment
  staging: comedi: mf6x4: Fix AI end-of-conversion detection
  staging: greybus: Add TODO item about modernizing the pwm code
  pinctrl: ralink: add a pinctrl driver for the rt2880 family
  dt-bindings: pinctrl: rt2880: add binding document
  staging: rtl8723bs: remove ELEMENT_ID enum
  staging: rtl8723bs: remove unused macros
  staging: rtl8723bs: replace EID_EXTCapability
  staging: rtl8723bs: replace EID_BSSIntolerantChlReport
  staging: rtl8723bs: replace EID_BSSCoexistence
  staging: rtl8723bs: replace _MME_IE_
  staging: rtl8723bs: replace _WAPI_IE_
  staging: rtl8723bs: replace _EXT_SUPPORTEDRATES_IE_
  staging: rtl8723bs: replace _ERPINFO_IE_
  staging: rtl8723bs: replace _CHLGETXT_IE_
  staging: rtl8723bs: replace _COUNTRY_IE_
  staging: rtl8723bs: replace _IBSS_PARA_IE_
  staging: rtl8723bs: replace _TIM_IE_
  ...

Merge tag 'char-misc-5.11-rc1' of git://git./linux/kernel/git/gregkh/char-misc

Pull char / misc driver updates from Greg KH:
 "Here is the big char/misc driver update for 5.11-rc1.

  Continuing the tradition of previous -rc1 pulls, there seems to be
  more and more tiny driver subsystems flowing through this tree.

  Lots of different things, all of which have been in linux-next for a
  while with no reported issues:

   - extcon driver updates

   - habannalab driver updates

   - mei driver updates

   - uio driver updates

   - binder fixes and features added

   - soundwire driver updates

   - mhi bus driver updates

   - phy driver updates

   - coresight driver updates

   - fpga driver updates

   - speakup driver updates

   - slimbus driver updates

   - various small char and misc driver updates"

* tag 'char-misc-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (305 commits)
  extcon: max77693: Fix modalias string
  extcon: fsa9480: Support TI TSU6111 variant
  extcon: fsa9480: Rewrite bindings in YAML and extend
  dt-bindings: extcon: add binding for TUSB320
  extcon: Add driver for TI TUSB320
  slimbus: qcom: fix potential NULL dereference in qcom_slim_prg_slew()
  siox: Make remove callback return void
  siox: Use bus_type functions for probe, remove and shutdown
  spmi: Add driver shutdown support
  spmi: fix some coding style issues at the spmi core
  spmi: get rid of a warning when built with W=1
  uio: uio_hv_generic: use devm_kzalloc() for private data alloc
  uio: uio_fsl_elbc_gpcm: use device-managed allocators
  uio: uio_aec: use devm_kzalloc() for uio_info object
  uio: uio_cif: use devm_kzalloc() for uio_info object
  uio: uio_netx: use devm_kzalloc() for or uio_info object
  uio: uio_mf624: use devm_kzalloc() for uio_info object
  uio: uio_sercos3: use device-managed functions for simple allocs
  uio: uio_dmem_genirq: finalize conversion of probe to devm_ handlers
  uio: uio_dmem_genirq: convert simple allocations to device-managed
  ...

Merge tag 'driver-core-5.11-rc1' of git://git./linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the big driver core updates for 5.11-rc1

  This time there was a lot of different work happening here for some
  reason:

   - redo of the fwnode link logic, speeding it up greatly

   - auxiliary bus added (this was a tag that will be pulled in from
     other trees/maintainers this merge window as well, as driver
     subsystems started to rely on it)

   - platform driver core cleanups on the way to fixing some long-time
     api updates in future releases

   - minor fixes and tweaks.

  All have been in linux-next with no (finally) reported issues. Testing
  there did helped in shaking issues out a lot :)"

* tag 'driver-core-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (39 commits)
  driver core: platform: don't oops in platform_shutdown() on unbound devices
  ACPI: Use fwnode_init() to set up fwnode
  misc: pvpanic: Replace OF headers by mod_devicetable.h
  misc: pvpanic: Combine ACPI and platform drivers
  usb: host: sl811: Switch to use platform_get_mem_or_io()
  vfio: platform: Switch to use platform_get_mem_or_io()
  driver core: platform: Introduce platform_get_mem_or_io()
  dyndbg: fix use before null check
  soc: fix comment for freeing soc_dev_attr
  driver core: platform: use bus_type functions
  driver core: platform: change logic implementing platform_driver_probe
  driver core: platform: reorder functions
  driver core: make driver_probe_device() static
  driver core: Fix a couple of typos
  driver core: Reorder devices on successful probe
  driver core: Delete pointless parameter in fwnode_operations.add_links
  driver core: Refactor fw_devlink feature
  efi: Update implementation of add_links() to create fwnode links
  of: property: Update implementation of add_links() to create fwnode links
  driver core: Use device's fwnode to check if it is waiting for suppliers
  ...

Merge tag 'tty-5.11-rc1' of git://git./linux/kernel/git/gregkh/tty

Pull tty / serial updates from Greg KH:
 "Here is the "large" set of tty and serial patches for 5.11-rc1.

  Nothing major at all, some cleanups and some driver removals, always a
  nice sign:

   - build warning cleanups

   - vt locking and logic unwinding and cleanups

   - tiny serial driver fixes and updates

   - removal of the synclink serial driver as it's no longer needed

   - removal of dead termiox code

  All of this has been in linux-next for a while with no reported issues"

* tag 'tty-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (89 commits)
  serial: 8250_pci: Drop bogus __refdata annotation
  tty: serial: meson: enable console as module
  serial: 8250_omap: Avoid FIFO corruption caused by MDR1 access
  serial: imx: Move imx_uart_probe_dt() content into probe()
  serial: imx: Remove unneeded of_device_get_match_data() NULL check
  tty: Fix whitespace inconsistencies in vt_io_ioctl
  serial_core: Check for port state when tty is in error state
  dt-bindings: serial: Update DT binding docs to support SiFive FU740 SoC
  tty: use const parameters in port-flag accessors
  tty: use assign_bit() in port-flag accessors
  earlycon: drop semicolon from earlycon macro
  tty: Remove dead termiox code
  tty/serial/imx: Enable TXEN bit in imx_poll_init().
  tty : serial: jsm: Fixed file by adding spacing
  tty: serial: uartlite: Support probe deferral
  earlycon: simplify earlycon-table implementation
  tty: serial: bcm63xx: lower driver dependencies
  serial: mxs-auart: Remove unneeded platform_device_id
  serial: 8250-mtk: Fix reference leak in mtk8250_probe
  serial: imx: Remove unused .id_table support
  ...

Merge tag 'usb-5.11-rc1' of git://git./linux/kernel/git/gregkh/usb

Pull USB / Thunderbolt updates from Greg KH:
 "Here is the big USB and thunderbolt pull request for 5.11-rc1.

  Nothing major in here, just the grind of constant development to
  support new hardware and fix old issues:

   - thunderbolt updates for new USB4 hardware

   - cdns3 major driver updates

   - lots of typec updates and additions as more hardware is available

   - usb serial driver updates and fixes

   - other tiny USB driver updates

  All have been in linux-next with no reported issues"

* tag 'usb-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (172 commits)
  usb: phy: convert comma to semicolon
  usb: ucsi: convert comma to semicolon
  usb: typec: tcpm: convert comma to semicolon
  usb: typec: tcpm: Update vbus_vsafe0v on init
  usb: typec: tcpci: Enable bleed discharge when auto discharge is enabled
  usb: typec: Add class for plug alt mode device
  USB: typec: tcpci: Add Bleed discharge to POWER_CONTROL definition
  USB: typec: tcpm: Add a 30ms room for tPSSourceOn in PR_SWAP
  USB: typec: tcpm: Fix PR_SWAP error handling
  USB: typec: tcpm: Hard Reset after not receiving a Request
  USB: gadget: f_fs: remove likely/unlikely
  usb: gadget: f_fs: Re-use SS descriptors for SuperSpeedPlus
  USB: gadget: f_midi: setup SuperSpeed Plus descriptors
  USB: gadget: f_acm: add support for SuperSpeed Plus
  USB: gadget: f_rndis: fix bitrate for SuperSpeed and above
  usb: typec: intel_pmc_mux: Configure cable generation value for USB4
  MAINTAINERS: Add myself as a reviewer for CADENCE USB3 DRD IP DRIVER
  usb: chipidea: ci_hdrc_imx: Use of_device_get_match_data()
  usb: chipidea: usbmisc_imx: Use of_device_get_match_data()
  usb: cdns3: fix NULL pointer dereference on no platform data
  ...

Merge tag 'sound-5.11-rc1' of git://git./linux/kernel/git/tiwai/sound

Pull sound updates from Takashi Iwai:
 "Lots of changes (slightly more code increase than usual) at this time,
  while most of code changes are ASoC driver-specific.

  Here are some highlights:

  Core:

   - The new auxiliary bus implementation for Intel DSP, which will be
     used by other drivers as well

   - Lots of ASoC core cleanups and refactoring

   - UBSAN and KCSAN fixes in rawmidi, sequencer and a few others

   - Compress-offload API enhancement for the pause during draining

  HD- and USB-audio:

   - Enhancements of the USB-audio implicit feedback support, including
     better full-duplex operations

   - Continued CA0132 improvements and fixes

   - A few new quirk entries, HDMI audio fixes

  ASoC:

   - Support for boot time selection of Intel DSP firmware, which should
     help distros/users testing new stuff more easily; the kconfig was
     moved to boot time option, too

   - Some basic DPCM support in audio graph card

   - Removal of old pre-DT Freescale drivers

   - Support for Allwinner H6 I2S, Analog Devices ADAU1372, Intel
     Alderlake-S, GMediatek MT8192, NXP i.MX HDMI and XCVR, Realtek
     RT715, Qualcomm SM8250 and simple GPIO based muxes"

* tag 'sound-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (445 commits)
  ALSA: pcm: oss: Fix potential out-of-bounds shift
  ALSA: usb-audio: Fix potential out-of-bounds shift
  ALSA: hda/ca0132 - Add ZxR surround DAC setup.
  ALSA: hda/ca0132 - Add 8051 PLL write helper functions.
  ALSA: hda/hdmi: packet buffer index must be set before reading value
  ASoC: SOF: imx: update kernel-doc description
  ASoC: mediatek: mt8183: delete some unreachable code
  ASoC: mediatek: mt8183: add PM ops to machine drivers
  ASoC: topology: Fix wrong size check
  ASoC: topology: Add missing size check
  ASoC: SOF: Intel: hda: fix the condition passed to sof_dev_dbg_or_err
  ASoC: SOF: modify the SOF_DBG flags
  ASoC: SOF: Intel: hda: remove duplicated status dump
  ASoC: rt1015p: delay 300ms after SDB pulling high for calibration
  ASoC: rt1015p: move SDB control from trigger to DAPM
  ASoC: wm_adsp: remove "ctl" from list on error in wm_adsp_create_control()
  ALSA: usb-audio: Fix control 'access overflow' errors from chmap
  ALSA: hda/hdmi: always print pin NIDs as hexadecimal
  ALSA: hda/realtek - Add supported for more Lenovo ALC285 Headset Button
  ALSA: hda/ca0132 - Remove now unnecessary DSP setup functions.
  ...

Merge tag 'net-next-5.11' of git://git./linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core:

   - support "prefer busy polling" NAPI operation mode, where we defer
     softirq for some time expecting applications to periodically busy
     poll

   - AF_XDP: improve efficiency by more batching and hindering the
     adjacency cache prefetcher

   - af_packet: make packet_fanout.arr size configurable up to 64K

   - tcp: optimize TCP zero copy receive in presence of partial or
     unaligned reads making zero copy a performance win for much smaller
     messages

   - XDP: add bulk APIs for returning / freeing frames

   - sched: support fragmenting IP packets as they come out of conntrack

   - net: allow virtual netdevs to forward UDP L4 and fraglist GSO skbs

  BPF:

   - BPF switch from crude rlimit-based to memcg-based memory accounting

   - BPF type format information for kernel modules and related tracing
     enhancements

   - BPF implement task local storage for BPF LSM

   - allow the FENTRY/FEXIT/RAW_TP tracing programs to use
     bpf_sk_storage

  Protocols:

   - mptcp: improve multiple xmit streams support, memory accounting and
     many smaller improvements

   - TLS: support CHACHA20-POLY1305 cipher

   - seg6: add support for SRv6 End.DT4/DT6 behavior

   - sctp: Implement RFC 6951: UDP Encapsulation of SCTP

   - ppp_generic: add ability to bridge channels directly

   - bridge: Connectivity Fault Management (CFM) support as is defined
     in IEEE 802.1Q section 12.14.

  Drivers:

   - mlx5: make use of the new auxiliary bus to organize the driver
     internals

   - mlx5: more accurate port TX timestamping support

   - mlxsw:
      - improve the efficiency of offloaded next hop updates by using
        the new nexthop object API
      - support blackhole nexthops
      - support IEEE 802.1ad (Q-in-Q) bridging

   - rtw88: major bluetooth co-existance improvements

   - iwlwifi: support new 6 GHz frequency band

   - ath11k: Fast Initial Link Setup (FILS)

   - mt7915: dual band concurrent (DBDC) support

   - net: ipa: add basic support for IPA v4.5

  Refactor:

   - a few pieces of in_interrupt() cleanup work from Sebastian Andrzej
     Siewior

   - phy: add support for shared interrupts; get rid of multiple driver
     APIs and have the drivers write a full IRQ handler, slight growth
     of driver code should be compensated by the simpler API which also
     allows shared IRQs

   - add common code for handling netdev per-cpu counters

   - move TX packet re-allocation from Ethernet switch tag drivers to a
     central place

   - improve efficiency and rename nla_strlcpy

   - number of W=1 warning cleanups as we now catch those in a patchwork
     build bot

  Old code removal:

   - wan: delete the DLCI / SDLA drivers

   - wimax: move to staging

   - wifi: remove old WDS wifi bridging support"

* tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1922 commits)
  net: hns3: fix expression that is currently always true
  net: fix proc_fs init handling in af_packet and tls
  nfc: pn533: convert comma to semicolon
  af_vsock: Assign the vsock transport considering the vsock address flags
  af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path
  vsock_addr: Check for supported flag values
  vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag
  vm_sockets: Add flags field in the vsock address data structure
  net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled
  tcp: Add logic to check for SYN w/ data in tcp_simple_retransmit
  net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context
  nfc: s3fwrn5: Release the nfc firmware
  net: vxget: clean up sparse warnings
  mlxsw: spectrum_router: Use eXtended mezzanine to offload IPv4 router
  mlxsw: spectrum: Set KVH XLT cache mode for Spectrum2/3
  mlxsw: spectrum_router_xm: Introduce basic XM cache flushing
  mlxsw: reg: Add Router LPM Cache Enable Register
  mlxsw: reg: Add Router LPM Cache ML Delete Register
  mlxsw: spectrum_router_xm: Implement L-value tracking for M-index
  mlxsw: reg: Add XM Router M Table Register
  ...

Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:

 - a few random little subsystems

 - almost all of the MM patches which are staged ahead of linux-next
   material. I'll trickle to post-linux-next work in as the dependents
   get merged up.

Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
  mm: cleanup kstrto*() usage
  mm: fix fall-through warnings for Clang
  mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
  mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
  mm:backing-dev: use sysfs_emit in macro defining functions
  mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
  mm: use sysfs_emit for struct kobject * uses
  mm: fix kernel-doc markups
  zram: break the strict dependency from lzo
  zram: add stat to gather incompressible pages since zram set up
  zram: support page writeback
  mm/process_vm_access: remove redundant initialization of iov_r
  mm/zsmalloc.c: rework the list_add code in insert_zspage()
  mm/zswap: move to use crypto_acomp API for hardware acceleration
  mm/zswap: fix passing zero to 'PTR_ERR' warning
  mm/zswap: make struct kernel_param_ops definitions const
  userfaultfd/selftests: hint the test runner on required privilege
  userfaultfd/selftests: fix retval check for userfaultfd_open()
  userfaultfd/selftests: always dump something in modes
  userfaultfd: selftests: make __{s,u}64 format specifiers portable
  ...

mm: cleanup kstrto*() usage

Range checks can folded into proper conversion function.  kstrto*() exist
for all arithmetic types.

Link: https://lkml.kernel.org/r/20201122123759.GC92364@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix a couple of
warnings by explicitly adding a break statement instead of just letting
the code fall through to the next, and by adding a fallthrough
pseudo-keyword in places where the code is intended to fall through.

Link: https://github.com/KSPP/linux/issues/115
Link: https://lkml.kernel.org/r/f5756988b8842a3f10008fbc5b0a654f828920a9.1605896059.git.gustavoars@kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at

Convert the unbounded uses of sprintf to sysfs_emit.

A few conversions may now not end in a newline if the output buffer is
overflowed.

Link: https://lkml.kernel.org/r/0c90a90f466167f8c37de4b737553cf49c4a277f.1605376435.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: shmem: convert shmem_enabled_show to use sysfs_emit_at

Update the function to use sysfs_emit_at while neatening the uses of
sprintf and overwriting the last space char with a newline to avoid
possible output buffer overflow.

Miscellanea:

 - in shmem_enabled_show, the removal of the indirected use of fmt
   allows __printf verification

Link: https://lkml.kernel.org/r/b612a93825e5ea330cb68d2e8b516e9687a06cc6.1605376435.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm:backing-dev: use sysfs_emit in macro defining functions

The cocci script used in commit bdacbb8d04f ("mm: Use sysfs_emit for
struct kobject * uses") does not convert the name##_show macro because the
macro uses concatenation via ##.

Convert it by hand.

Link: https://lkml.kernel.org/r/45ec6cfc177d743f9c0ebaf35e43969dce43af42.1605376435.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening

Convert the only use of sprintf with struct kobject * that the cocci
script could not convert.

Miscellanea:

 - Neaten the uses of a constant string with sysfs_emit to use a const
   char * to reduce overall object size

Link: https://lkml.kernel.org/r/7df6be66bbd68e1a0bca9d35aca1341dbf94d2a7.1605376435.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: use sysfs_emit for struct kobject * uses

Patch series "mm: Convert sysfs sprintf family to sysfs_emit", v2.

Use the new sysfs_emit family and not the sprintf family.

This patch (of 5):

Use the sysfs_emit function instead of the sprintf family.

Done with cocci script as in commit 3c6bff3cf988 ("RDMA: Convert sysfs
kobject * show functions to use sysfs_emit()")

Link: https://lkml.kernel.org/r/cover.1605376435.git.joe@perches.com
Link: https://lkml.kernel.org/r/9c249215bad6df616ba0410ad980042694970c1b.1605376435.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: fix kernel-doc markups

Kernel-doc markups should use this format:
        identifier - description

Fix some issues on mm files:

1) The definition for get_user_pages_locked() doesn't follow it.  Also,
   it expects a short descrpition at the header, followed by a long one,
   after the parameters.  Fix it.

2) Kernel-doc requires that a kernel-doc markup to be immediately below
   the function prototype, as otherwise it will rename it.  So, move
   get_pfnblock_flags_mask() description to the right place.

3) Make invalidate_mapping_pagevec() to also follow the expected
   kernel-doc format.

While here, fix a few minor English syntax issues, as suggested
by Matthew:
will used -> will be used
similar with -> similar to

Link: https://lkml.kernel.org/r/80e85dddc92d333bc2159ee8a2294921612e8745.1605521731.git.mchehab+huawei@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Suggested-by: Mattew Wilcox <willy@infradead.org> [English fixes]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

zram: break the strict dependency from lzo

From the beginning, the zram block device always enabled CRYPTO_LZO,
since lzo-rle is hardcoded as the fallback compression algorithm.  As a
consequence, on systems where another compression algorithm is chosen
(e.g.  CRYPTO_ZSTD), the lzo kernel module becomes unused, while still
having to be built/loaded.

This patch removes the hardcoded lzo-rle dependency and allows the user
to select the default compression algorithm for zram at build time.  The
previous behaviour is kept, as the default algorithm is still lzo-rle.

Link: https://lkml.kernel.org/r/20201207121245.50529-1-rsalvaterra@gmail.com
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
Suggested-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

zram: add stat to gather incompressible pages since zram set up

Currently, zram supports the stat via /sys/block/zram/mm_stat to represent
how many of incompressible pages are stored at the moment but it couldn't
show how many times incompressible pages were wrote down since zram set
up.  It's also good indication to see how zram is effective in the system.

Link: https://lkml.kernel.org/r/20201130201907.1284910-1-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

zram: support page writeback

There is demand to writeback specific process pages to backing store
instead of all idles pages in the system due to storage wear out concerns
and to launching latency of apps which are most of the time idle but are
critical for resume latency.

This patch extends the writeback knob to support a specific page
writeback.

Link: https://lkml.kernel.org/r/20201020190506.3758660-1-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/process_vm_access: remove redundant initialization of iov_r

The pointer iov_r is being initialized with a value that is never read and
it is being updated later with a new value.  The initialization is
redundant and can be removed.

Link: https://lkml.kernel.org/r/20201102120614.694917-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/zsmalloc.c: rework the list_add code in insert_zspage()

Rework the list_add code to make it more readable and simple.

Link: https://lkml.kernel.org/r/20201015130107.65195-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/zswap: move to use crypto_acomp API for hardware acceleration

Right now, all new ZIP drivers are adapted to crypto_acomp APIs rather
than legacy crypto_comp APIs.  Tradiontal ZIP drivers like lz4,lzo etc
have been also wrapped into acomp via scomp backend.  But zswap.c is still
using the old APIs.  That means zswap won't be able to work on any new ZIP
drivers in kernel.

This patch moves to use cryto_acomp APIs to fix the disconnected bridge
between new ZIP drivers and zswap.  It is probably the first real user to
use acomp but perhaps not a good example to demonstrate how multiple acomp
requests can be executed in parallel in one acomp instance.  frontswap is
doing page load and store page by page synchronously.  swap_writepage()
depends on the completion of frontswap_store() to decide if it should call
__swap_writepage() to swap to disk.

However this patch creates multiple acomp instances, so multiple threads
running on multiple different cpus can actually do (de)compression
parallelly, leveraging the power of multiple ZIP hardware queues.  This is
also consistent with frontswap's page management model.

The old zswap code uses atomic context and avoids the race conditions
while shared resources like zswap_dstmem are accessed.  Here since acomp
can sleep, per-cpu mutex is used to replace preemption-disable.

While it is possible to make mm/page_io.c and mm/frontswap.c support async
(de)compression in some way, the entire design requires careful thinking
and performance evaluation.  For the first step, the base with fixed
connection between ZIP drivers and zswap should be built.

Link: https://lkml.kernel.org/r/20201107065332.26992-1-song.bao.hua@hisilicon.com
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Acked-by: Vitaly Wool <vitalywool@gmail.com>
Cc: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Mahipal Challa <mahipalreddy2006@gmail.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Zhou Wang <wangzhou1@hisilicon.com>
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/zswap: fix passing zero to 'PTR_ERR' warning

Fix smatch warning:

  mm/zswap.c:425 zswap_cpu_comp_prepare() warn: passing zero to 'PTR_ERR'

crypto_alloc_comp() never return NULL, use IS_ERR instead of
IS_ERR_OR_NULL to fix this.

Link: https://lkml.kernel.org/r/20201031055615.28080-1-yuehaibing@huawei.com
Fixes: f1c54846ee45 ("zswap: dynamic pool creation")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/zswap: make struct kernel_param_ops definitions const

These should be const, so make it so.

Link: https://lkml.kernel.org/r/1791535ee0b00f4a5c68cc4a8adada06593ad8f1.1601770305.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

userfaultfd/selftests: hint the test runner on required privilege

Now userfaultfd test program requires either root or ptrace privilege due
to the signal/event tests.  When UFFDIO_API failed, hint the test runner
about this fact verbosely.

Link: https://lkml.kernel.org/r/20201208024709.7701-4-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

userfaultfd/selftests: fix retval check for userfaultfd_open()

userfaultfd_open() returns 1 for errors rather than negatives.  Fix it on
all the callers so when UFFDIO_API failed the test will bail out.

Link: https://lkml.kernel.org/r/20201208024709.7701-3-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

userfaultfd/selftests: always dump something in modes

Patch series "userfaultfd: selftests: Small fixes".

Some very trivial fixes that I kept locally to userfaultfd selftest
program.

This patch (of 3):

BOUNCE_POLL is a special bit that if cleared it means "READ" instead.
Dump that too otherwise we'll see tests with empty modes.

Link: https://lkml.kernel.org/r/20201208024709.7701-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20201208024709.7701-2-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

userfaultfd: selftests: make __{s,u}64 format specifiers portable

On certain platforms (powerpcle is the one on which I ran into this),
"%Ld" and "%Lu" are unsuitable for printing __s64 and __u64, respectively,
resulting in build warnings.  Cast to {u,}int64_t, and use the PRI{d,u}64
macros defined in inttypes.h to print them.  This ought to be portable to
all platforms.

Splitting this off into a separate macro lets us remove some lines, and
get rid of some (I would argue) stylistically odd cases where we joined
printf() and exit() into a single statement with a ,.

Finally, this also fixes a "missing braces around initializer" warning
when we initialize prms in wp_range().

[axelrasmussen@google.com: v2]
Link: https://lkml.kernel.org/r/20201203180244.1811601-1-axelrasmussen@google.com
Link: https://lkml.kernel.org/r/20201202211542.1121189-1-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Alan Gilbert <dgilbert@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

userfaultfd: add user-mode only option to unprivileged_userfaultfd sysctl knob

With this change, when the knob is set to 0, it allows unprivileged users
to call userfaultfd, like when it is set to 1, but with the restriction
that page faults from only user-mode can be handled.  In this mode, an
unprivileged user (without SYS_CAP_PTRACE capability) must pass
UFFD_USER_MODE_ONLY to userfaultd or the API will fail with EPERM.

This enables administrators to reduce the likelihood that an attacker with
access to userfaultfd can delay faulting kernel code to widen timing
windows for other exploits.

The default value of this knob is changed to 0.  This is required for
correct functioning of pipe mutex.  However, this will fail postcopy live
migration, which will be unnoticeable to the VM guests.  To avoid this,
set 'vm.userfault = 1' in /sys/sysctl.conf.

The main reason this change is desirable as in the short term is that the
Android userland will behave as with the sysctl set to zero.  So without
this commit, any Linux binary using userfaultfd to manage its memory would
behave differently if run within the Android userland.  For more details,
refer to Andrea's reply [1].

[1] https://lore.kernel.org/lkml/20200904033438.GI9411@redhat.com/

Link: https://lkml.kernel.org/r/20201120030411.2690816-3-lokeshgidra@google.com
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Daniel Colascione <dancol@dancol.org>
Cc: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: <calin@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Nitin Gupta <nigupta@nvidia.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Daniel Colascione <dancol@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

userfaultfd: add UFFD_USER_MODE_ONLY

Patch series "Control over userfaultfd kernel-fault handling", v6.

This patch series is split from [1].  The other series enables SELinux
support for userfaultfd file descriptors so that its creation and movement
can be controlled.

It has been demonstrated on various occasions that suspending kernel code
execution for an arbitrary amount of time at any access to userspace
memory (copy_from_user()/copy_to_user()/...) can be exploited to change
the intended behavior of the kernel.  For instance, handling page faults
in kernel-mode using userfaultfd has been exploited in [2, 3].  Likewise,
FUSE, which is similar to userfaultfd in this respect, has been exploited
in [4, 5] for similar outcome.

This small patch series adds a new flag to userfaultfd(2) that allows
callers to give up the ability to handle kernel-mode faults with the
resulting UFFD file object.  It then adds a 'user-mode only' option to the
unprivileged_userfaultfd sysctl knob to require unprivileged callers to
use this new flag.

The purpose of this new interface is to decrease the chance of an
unprivileged userfaultfd user taking advantage of userfaultfd to enhance
security vulnerabilities by lengthening the race window in kernel code.

[1] https://lore.kernel.org/lkml/20200211225547.235083-1-dancol@google.com/
[2] https://duasynt.com/blog/linux-kernel-heap-spray
[3] https://duasynt.com/blog/cve-2016-6187-heap-off-by-one-exploit
[4] https://googleprojectzero.blogspot.com/2016/06/exploiting-recursion-in-linux-kernel_20.html
[5] https://bugs.chromium.org/p/project-zero/issues/detail?id=808

This patch (of 2):

userfaultfd handles page faults from both user and kernel code.  Add a new
UFFD_USER_MODE_ONLY flag for userfaultfd(2) that makes the resulting
userfaultfd object refuse to handle faults from kernel mode, treating
these faults as if SIGBUS were always raised, causing the kernel code to
fail with EFAULT.

A future patch adds a knob allowing administrators to give some processes
the ability to create userfaultfd file objects only if they pass
UFFD_USER_MODE_ONLY, reducing the likelihood that these processes will
exploit userfaultfd's ability to delay kernel page faults to open timing
windows for future exploits.

Link: https://lkml.kernel.org/r/20201120030411.2690816-1-lokeshgidra@google.com
Link: https://lkml.kernel.org/r/20201120030411.2690816-2-lokeshgidra@google.com
Signed-off-by: Daniel Colascione <dancol@google.com>
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: <calin@google.com>
Cc: Daniel Colascione <dancol@dancol.org>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nitin Gupta <nigupta@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shaohua Li <shli@fb.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO

CONFIG_PAGE_POISONING_ZERO uses the zero pattern instead of 0xAA.  It was
introduced by commit 1414c7f4f7d7 ("mm/page_poisoning.c: allow for zero
poisoning"), noting that using zeroes retains the benefit of sanitizing
content of freed pages, with the benefit of not having to zero them again
on alloc, and the downside of making some forms of corruption (stray
writes of NULLs) harder to detect than with the 0xAA pattern.  Together
with CONFIG_PAGE_POISONING_NO_SANITY it made possible to sanitize the
contents on free without checking it back on alloc.

These days we have the init_on_free() option to achieve sanitization with
zeroes and to save clearing on alloc (and without checking on alloc).
Arguably if someone does choose to check the poison for corruption on
alloc, the savings of not clearing the page are secondary, and it makes
sense to always use the 0xAA poison pattern.  Thus, remove the
CONFIG_PAGE_POISONING_ZERO option for being redundant.

Link: https://lkml.kernel.org/r/20201113104033.22907-6-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, page_poison: remove CONFIG_PAGE_POISONING_NO_SANITY

CONFIG_PAGE_POISONING_NO_SANITY skips the check on page alloc whether the
poison pattern was corrupted, suggesting a use-after-free.  The motivation
to introduce it in commit 8823b1dbc05f ("mm/page_poison.c: enable
PAGE_POISONING as a separate option") was to simply sanitize freed pages,
optimally together with CONFIG_PAGE_POISONING_ZERO.

These days we have an init_on_free=1 boot option, which makes this use
case of page poisoning redundant.  For sanitizing, writing zeroes is
sufficient, there is pretty much no benefit from writing the 0xAA poison
pattern to freed pages, without checking it back on alloc.  Thus, remove
this option and suggest init_on_free instead in the main config's help.

Link: https://lkml.kernel.org/r/20201113104033.22907-5-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/power: allow hibernation with page_poison sanity checking

Page poisoning used to be incompatible with hibernation, as the state of
poisoned pages was lost after resume, thus enabling CONFIG_HIBERNATION
forces CONFIG_PAGE_POISONING_NO_SANITY.  For the same reason, the
poisoning with zeroes variant CONFIG_PAGE_POISONING_ZERO used to disable
hibernation.  The latter restriction was removed by commit 1ad1410f632d
("PM / Hibernate: allow hibernation with PAGE_POISONING_ZERO") and
similarly for init_on_free by commit 18451f9f9e58 ("PM: hibernate: fix
crashes with init_on_free=1") by making sure free pages are cleared after
resume.

We can use the same mechanism to instead poison free pages with
PAGE_POISON after resume.  This covers both zero and 0xAA patterns.  Thus
we can remove the Kconfig restriction that disables page poison sanity
checking when hibernation is enabled.

Link: https://lkml.kernel.org/r/20201113104033.22907-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [hibernation]
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, page_poison: use static key more efficiently

Commit 11c9c7edae06 ("mm/page_poison.c: replace bool variable with static
key") changed page_poisoning_enabled() to a static key check.  However,
the function is not inlined, so each check still involves a function call
with overhead not eliminated when page poisoning is disabled.

Analogically to how debug_pagealloc is handled, this patch converts
page_poisoning_enabled() back to boolean check, and introduces
page_poisoning_enabled_static() for fast paths.  Both functions are
inlined.

The function kernel_poison_pages() is also called unconditionally and does
the static key check inside.  Remove it from there and put it to callers.
Also split it to two functions kernel_poison_pages() and
kernel_unpoison_pages() instead of the confusing bool parameter.

Also optimize the check that enables page poisoning instead of
debug_pagealloc for architectures without proper debug_pagealloc support.
Move the check to init_mem_debugging_and_hardening() to enable a single
static key instead of having two static branches in
page_poisoning_enabled_static().

Link: https://lkml.kernel.org/r/20201113104033.22907-3-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, page_alloc: do not rely on the order of page_poison and init_on_alloc/free parameters

Patch series "cleanup page poisoning", v3.

I have identified a number of issues and opportunities for cleanup with
CONFIG_PAGE_POISON and friends:

 - interaction with init_on_alloc and init_on_free parameters depends on
   the order of parameters (Patch 1)

 - the boot time enabling uses static key, but inefficienty (Patch 2)

 - sanity checking is incompatible with hibernation (Patch 3)

 - CONFIG_PAGE_POISONING_NO_SANITY can be removed now that we have
   init_on_free (Patch 4)

 - CONFIG_PAGE_POISONING_ZERO can be most likely removed now that we
   have init_on_free (Patch 5)

This patch (of 5):

Enabling page_poison=1 together with init_on_alloc=1 or init_on_free=1
produces a warning in dmesg that page_poison takes precedence.  However,
as these warnings are printed in early_param handlers for
init_on_alloc/free, they are not printed if page_poison is enabled later
on the command line (handlers are called in the order of their
parameters), or when init_on_alloc/free is always enabled by the
respective config option - before the page_poison early param handler is
called, it is not considered to be enabled.  This is inconsistent.

We can remove the dependency on order by making the init_on_* parameters
only set a boolean variable, and postponing the evaluation after all early
params have been processed.  Introduce a new
init_mem_debugging_and_hardening() function for that, and move the related
debug_pagealloc processing there as well.

As a result init_mem_debugging_and_hardening() knows always accurately if
init_on_* and/or page_poison options were enabled.  Thus we can also
optimize want_init_on_alloc() and want_init_on_free().  We don't need to
check page_poisoning_enabled() there, we can instead not enable the
init_on_* static keys at all, if page poisoning is enabled.  This results
in a simpler and more effective code.

Link: https://lkml.kernel.org/r/20201113104033.22907-1-vbabka@suse.cz
Link: https://lkml.kernel.org/r/20201113104033.22907-2-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Laura Abbott <labbott@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: cma: improve pr_debug log in cma_release()

It is required to print 'count' of pages, along with the pages, passed to
cma_release to debug the cases of mismatched count value passed between
cma_alloc() and cma_release() from a code path.

As an example, consider the below scenario:

1) CMA pool size is 4MB and

2) User doing the erroneous step of allocating 2 pages but freeing 1
   page in a loop from this CMA pool.  The step 2 causes cma_alloc() to
   return NULL at one point of time because of -ENOMEM condition.

And the current pr_debug logs is not giving the info about these types of
allocation patterns because of count value not being printed in
cma_release().

We are printing the count value in the trace logs, just extend the same to
pr_debug logs too.

[akpm@linux-foundation.org: fix printk warning]

Link: https://lkml.kernel.org/r/1606318341-29521-1-git-send-email-charante@codeaurora.org
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Reviewed-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/cma.c: remove redundant cma_mutex lock

The cma_mutex which protects alloc_contig_range() was first appeared in
commit 7ee793a62fa8c ("cma: Remove potential deadlock situation"), at that
time, there is no guarantee the behavior of concurrency inside
alloc_contig_range().

After commit 2c7452a075d4db2dc ("mm/page_isolation.c: make
start_isolate_page_range() fail if already isolated")

  > However, two subsystems (CMA and gigantic
  > huge pages for example) could attempt operations on the same range.  If
  > this happens, one thread may 'undo' the work another thread is doing.
  > This can result in pageblocks being incorrectly left marked as
  > MIGRATE_ISOLATE and therefore not available for page allocation.

The concurrency inside alloc_contig_range() was clarified.

Now we can find that hugepage and virtio call alloc_contig_range() without
any lock, thus cma_mutex is "redundant" in cma_alloc() now.

Link: https://lkml.kernel.org/r/20201020102241.3729-1-lecopzer.chen@mediatek.com
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: YJ Chiang <yj.chiang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: migrate: remove unused parameter in migrate_vma_insert_page()

"dst" parameter to migrate_vma_insert_page() is not used anymore.

Link: https://lkml.kernel.org/r/CANubcdUwCAMuUyamG2dkWP=cqSR9MAS=tHLDc95kQkqU-rEnAg@mail.gmail.com
Signed-off-by: Stephen Zhang <starzhangzsd@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: migrate: return -ENOSYS if THP migration is unsupported

In the current implementation unmap_and_move() would return -ENOMEM if THP
migration is unsupported, then the THP will be split.  If split is failed
just exit without trying to migrate other pages.  It doesn't make too much
sense since there may be enough free memory to migrate other pages and
there may be a lot base pages on the list.

Return -ENOSYS to make consistent with hugetlb.  And if THP split is
failed just skip and try other pages on the list.

Just skip the whole list and exit when free memory is really low.

Link: https://lkml.kernel.org/r/20201113205359.556831-6-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: migrate: clean up migrate_prep{_local}

The migrate_prep{_local} never fails, so it is pointless to have return
value and check the return value.

Link: https://lkml.kernel.org/r/20201113205359.556831-5-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: migrate: skip shared exec THP for NUMA balancing

The NUMA balancing skip shared exec base page.  Since
CONFIG_READ_ONLY_THP_FOR_FS was introduced, there are probably shared exec
THP, so skip such THPs for NUMA balancing as well.

And Willy's regular filesystem THP support patches could create shared
exec THP wven without that config.

In addition, the page_is_file_lru() is used to tell if the page is file
cache or not, but it filters out shmem page.  It sounds like a typical
usecase by putting executables in shmem to achieve performance gain via
using shmem-THP, so it sounds worth skipping migration for such case too.

Link: https://lkml.kernel.org/r/20201113205359.556831-4-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: migrate: simplify the logic for handling permanent failure

When unmap_and_move{_huge_page}() returns !-EAGAIN and
!MIGRATEPAGE_SUCCESS, the page would be put back to LRU or proper list if
it is non-LRU movable page.  But, the callers always call
putback_movable_pages() to put the failed pages back later on, so it seems
not very efficient to put every single page back immediately, and the code
looks convoluted.

Put the failed page on a separate list, then splice the list to migrate
list when all pages are tried.  It is the caller's responsibility to call
putback_movable_pages() to handle failures.  This also makes the code
simpler and more readable.

After the change the rules are:
    * Success: non hugetlb page will be freed, hugetlb page will be put
               back
    * -EAGAIN: stay on the from list
    * -ENOMEM: stay on the from list
    * Other errno: put on ret_pages list then splice to from list

The from list would be empty iff all pages are migrated successfully, it
was not so before.  This has no impact to current existing callsites.

Link: https://lkml.kernel.org/r/20201113205359.556831-3-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: truncate_complete_page() does not exist any more

Patch series "mm: misc migrate cleanup and improvement", v3.

This patch (of 5):

The commit 9f4e41f4717832e ("mm: refactor truncate_complete_page()")
refactored truncate_complete_page(), and it is not existed anymore,
correct the comment in vmscan and migrate to avoid confusion.

Link: https://lkml.kernel.org/r/20201113205359.556831-1-shy828301@gmail.com
Link: https://lkml.kernel.org/r/20201113205359.556831-2-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: support THPs in zero_user_segments

We can only kmap() one subpage of a THP at a time, so loop over all
relevant subpages, skipping ones which don't need to be zeroed.  This is
too large to inline when THPs are enabled and we actually need highmem, so
put it in highmem.c.

[willy@infradead.org: start1 was allowed to be less than start2]

Link: https://lkml.kernel.org/r/20201124041507.28996-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migrate.c: optimize migrate_vma_pages() mmu notifier

When migrating a zero page or pte_none() anonymous page to device private
memory, migrate_vma_setup() will initialize the src[] array with a NULL
PFN.  This lets the device driver allocate device private memory and clear
it instead of DMAing a page of zeros over the device bus.

Since the source page didn't exist at the time, no struct page was locked
nor a migration PTE inserted into the CPU page tables.  The actual PTE
insertion happens in migrate_vma_pages() when it tries to insert the
device private struct page PTE into the CPU page tables.
migrate_vma_pages() has to call the mmu notifiers again since another
device could fault on the same page before the page table locks are
acquired.

Allow device drivers to optimize the invalidation similar to
migrate_vma_setup() by calling mmu_notifier_range_init() which sets struct
mmu_notifier_range event type to MMU_NOTIFY_MIGRATE and the
migrate_pgmap_owner field.

Link: https://lkml.kernel.org/r/20201021191335.10916-1-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migrate.c: fix comment spelling

The word in the comment is misspelled, it should be "include".

Link: https://lkml.kernel.org/r/20201024114144.GA20552@lilong
Signed-off-by: Long Li <lonuxli.64@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/oom_kill: change comment and rename is_dump_unreclaim_slabs()

Change the comment of is_dump_unreclaim_slabs(), it just check whether
nr_unreclaimable slabs amount is greater than user memory, and explain why
we dump unreclaim slabs.

Rename it to should_dump_unreclaim_slab() maybe better.

Link: https://lkml.kernel.org/r/20201030182704.GA53949@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/compaction: make defer_compaction and compaction_deferred static

defer_compaction() and compaction_deferred() and compaction_restarting()
in mm/compaction.c won't be used in other files, so make them static, and
remove the declaration in the header file.

Take the chance to fix a typo.

Link: https://lkml.kernel.org/r/20201123170801.GA9625@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Nitin Gupta <nigupta@nvidia.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Mateusz Nosek <mateusznosek0@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/compaction: move compaction_suitable's comment to right place

Since commit 837d026d560c ("mm/compaction: more trace to understand
when/why compaction start/finish"), the comment place is not suitable.

So move compaction_suitable's comment to right place.

Link: https://lkml.kernel.org/r/20201116144121.GA385717@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/compaction: rename 'start_pfn' to 'iteration_start_pfn' in compact_zone()

There are two 'start_pfn' declared in compact_zone() which have different
meanings.  Rename the second one to 'iteration_start_pfn' to prevent
confusion.

Also, remove an useless semicolon.

Link: https://lkml.kernel.org/r/20201019115044.1571-1-yanfei.xu@windriver.com
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

z3fold: remove preempt disabled sections for RT

Replace get_cpu_ptr() with migrate_disable()+this_cpu_ptr() so RT can take
spinlocks that become sleeping locks.

Signed-off-by Mike Galbraith <efault@gmx.de>

Link: https://lkml.kernel.org/r/20201209145151.18994-3-vitaly.wool@konsulko.com
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

z3fold: stricter locking and more careful reclaim

Use temporary slots in reclaim function to avoid possible race when
freeing those.

While at it, make sure we check CLAIMED flag under page lock in the
reclaim function to make sure we are not racing with z3fold_alloc().

Link: https://lkml.kernel.org/r/20201209145151.18994-4-vitaly.wool@konsulko.com
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: <stable@vger.kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

z3fold: simplify freeing slots

Patch series "z3fold: stability / rt fixes".

Address z3fold stability issues under stress load, primarily in the
reclaim and free aspects.  Besides, it fixes the locking problems that
were only seen in real-time kernel configuration.

This patch (of 3):

There used to be two places in the code where slots could be freed, namely
when freeing the last allocated handle from the slots and when releasing
the z3fold header these slots aree linked to.  The logic to decide on
whether to free certain slots was complicated and error prone in both
functions and it led to failures in RT case.

To fix that, make free_handle() the single point of freeing slots.

Link: https://lkml.kernel.org/r/20201209145151.18994-1-vitaly.wool@konsulko.com
Link: https://lkml.kernel.org/r/20201209145151.18994-2-vitaly.wool@konsulko.com
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Tested-by: Mike Galbraith <efault@gmx.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_isolation: do not isolate the max order page

A max order page has no buddy page and never merges to another order.  So
isolating and then freeing it is pointless.

Link: https://lkml.kernel.org/r/20201202122114.75316-1-songmuchun@bytedance.com
Fixes: 3c605096d315 ("mm/page_alloc: restrict max order of merging on isolated pageblock")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan.c: remove the filename in the top of file comment

No point in having the filename inside the file.

Link: https://lkml.kernel.org/r/20201115141541.3878-1-hymmsx.yu@gmail.com
Signed-off-by: logic.yu <hymmsx.yu@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan: drop unneeded assignment in kswapd()

The refactoring to kswapd() in commit e716f2eb24de ("mm, vmscan: prevent
kswapd sleeping prematurely due to mismatched classzone_idx") turned an
assignment to reclaim_order into a dead store, as in all further paths,
reclaim_order will be assigned again before it is used.

make clang-analyzer on x86_64 tinyconfig caught my attention with:

  mm/vmscan.c: warning: Although the value stored to 'reclaim_order' is used in the enclosing expression, the value is never actually read from 'reclaim_order' [clang-analyzer-deadcode.DeadStores]

Compilers will detect this unneeded assignment and optimize this anyway.
So, the resulting binary is identical before and after this change.

Simplify the code and remove unneeded assignment to make clang-analyzer
happy.

No functional change. No change in binary code.

Link: https://lkml.kernel.org/r/20201004125827.17679-1-lukas.bulwahn@gmail.com
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: don't wake kswapd prematurely when watermark boosting is disabled

On 2-node NUMA hosts we see bursts of kswapd reclaim and subsequent
pressure spikes and stalls from cache refaults while there is plenty of
free memory in the system.

Usually, kswapd is woken up when all eligible nodes in an allocation are
full.  But the code related to watermark boosting can wake kswapd on one
full node while the other one is mostly empty.  This may be justified to
fight fragmentation, but is currently unconditionally done whether
watermark boosting is occurring or not.

In our case, many of our workloads' throughput scales with available
memory, and pure utilization is a more tangible concern than trends
around longer-term fragmentation.  As a result we generally disable
watermark boosting.

Wake kswapd only woken when watermark boosting is requested.

Link: https://lkml.kernel.org/r/20201020175833.397286-1-hannes@cmpxchg.org
Fixes: 1c30844d2dfe ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

hugetlb: fix an error code in hugetlb_reserve_pages()

Preserve the error code from region_add() instead of returning success.

Link: https://lkml.kernel.org/r/X9NGZWnZl5/Mt99R@mwanda
Fixes: 0db9d74ed884 ("hugetlb: disable region_add file_region coalescing")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm,hugetlb: remove unneeded initialization

hugetlb_add_hstate initializes nr_huge_pages and free_huge_pages to 0, but
since hstates[] is a global variable, all its fields are defined to 0
already.

Link: https://lkml.kernel.org/r/20201119112141.6452-1-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: hugetlb: fix type of delta parameter and related local variables in gather_surplus_pages()

On 64-bit machine, delta variable in hugetlb_acct_memory() may be larger
than 0xffffffff, but gather_surplus_pages() can only use the low 32-bit
value now.  So we need to fix type of delta parameter and related local
variables in gather_surplus_pages().

Link: https://lkml.kernel.org/r/1605793733-3573-1-git-send-email-liu.xiang@zlingsmart.com
Reported-by: Ma Chenggong <ma.chenggong@zlingsmart.com>
Signed-off-by: Liu Xiang <liu.xiang@zlingsmart.com>
Signed-off-by: Pan Jiagen <pan.jiagen@zlingsmart.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Liu Xiang <liuxiang_1999@126.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

khugepaged: add parameter explanations for kernel-doc markup

Add missed parameter explanation for some kernel-doc warnings:

  mm/khugepaged.c:102: warning: Function parameter or member 'nr_pte_mapped_thp' not described in 'mm_slot'
  mm/khugepaged.c:102: warning: Function parameter or member 'pte_mapped_thp' not described in 'mm_slot'
  mm/khugepaged.c:1424: warning: Function parameter or member 'mm' not described in 'collapse_pte_mapped_thp'
  mm/khugepaged.c:1424: warning: Function parameter or member 'addr' not described in 'collapse_pte_mapped_thp'
  mm/khugepaged.c:1626: warning: Function parameter or member 'mm' not described in 'collapse_file'
  mm/khugepaged.c:1626: warning: Function parameter or member 'file' not described in 'collapse_file'
  mm/khugepaged.c:1626: warning: Function parameter or member 'start' not described in 'collapse_file'
  mm/khugepaged.c:1626: warning: Function parameter or member 'hpage' not described in 'collapse_file'
  mm/khugepaged.c:1626: warning: Function parameter or member 'node' not described in 'collapse_file'

Link: https://lkml.kernel.org/r/1605597325-25284-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/huge_mm.h: remove extern keyword

The external function definitions don't need the "extern" keyword.  Remove
them so future changes don't copy the function definition style.

Link: https://lkml.kernel.org/r/20201106235135.32109-1-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hugetlb.c: just use put_page_testzero() instead of page_count()

We test the page reference count is zero or not here, it can be a bug here
if page refercence count is not zero.  So we can just use
put_page_testzero() instead of page_count().

Link: https://lkml.kernel.org/r/20201007170949.GA6416@rlk
Signed-off-by: Hui Su <sh_def@163.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm,hwpoison: return -EBUSY when migration fails

Currently, we return -EIO when we fail to migrate the page.

Migrations' failures are rather transient as they can happen due to
several reasons, e.g: high page refcount bump, mapping->migrate_page
failing etc.  All meaning that at that time the page could not be
migrated, but that has nothing to do with an EIO error.

Let us return -EBUSY instead, as we do in case we failed to isolate the
page.

While are it, let us remove the "ret" print as its value does not change.

Link: https://lkml.kernel.org/r/20201209092818.30417-1-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm,memory_failure: always pin the page in madvise_inject_error

madvise_inject_error() uses get_user_pages_fast to translate the address
we specified to a page.  After [1], we drop the extra reference count for
memory_failure() path.  That commit says that memory_failure wanted to
keep the pin in order to take the page out of circulation.

The truth is that we need to keep the page pinned, otherwise the page
might be re-used after the put_page() and we can end up messing with
someone else's memory.

E.g:

CPU0
process X CPU1
 madvise_inject_error
  get_user_pages
   put_page
page gets reclaimed
process Y allocates the page
  memory_failure
   // We mess with process Y memory

madvise() is meant to operate on a self address space, so messing with
pages that do not belong to us seems the wrong thing to do.
To avoid that, let us keep the page pinned for memory_failure as well.

Pages for DAX mappings will release this extra refcount in
memory_failure_dev_pagemap.

[1] ("23e7b5c2e271: mm, madvise_inject_error:
      Let memory_failure() optionally take a page reference")

Link: https://lkml.kernel.org/r/20201207094818.8518-1-osalvador@suse.de
Fixes: 23e7b5c2e271 ("mm, madvise_inject_error: Let memory_failure() optionally take a page reference")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm,hwpoison: remove drain_all_pages from shake_page

get_hwpoison_page already drains pcplists, previously disabling them when
trying to grab a refcount.  We do not need shake_page to take care of it
anymore.

Link: https://lkml.kernel.org/r/20201204102558.31607-4-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Qian Cai <qcai@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm,hwpoison: disable pcplists before grabbing a refcount

Currently, we have a sort of retry mechanism to make sure pages in
pcp-lists are spilled to the buddy system, so we can handle those.

We can save us this extra checks with the new disable-pcplist mechanism
that is available with [1].

zone_pcplist_disable makes sure to 1) disable pcplists, so any page that
is freed up from that point onwards will end up in the buddy system and 2)
drain pcplists, so those pages that already in pcplists are spilled to
buddy.

With that, we can make a common entry point for grabbing a refcount from
both soft_offline and memory_failure paths that is guarded by
zone_pcplist_disable/zone_pcplist_enable.

[1] https://patchwork.kernel.org/project/linux-mm/cover/20201111092812.11329-1-vbabka@suse.cz/

Link: https://lkml.kernel.org/r/20201204102558.31607-3-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Qian Cai <qcai@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm,hwpoison: refactor get_any_page

Patch series "HWPoison: Refactor get page interface", v2.

This patch (of 3):

When we want to grab a refcount via get_any_page, we call __get_any_page
that calls get_hwpoison_page to get the actual refcount.

get_any_page() is only there because we have a sort of retry mechanism in
case the page we met is unknown to us or if we raced with an allocation.

Also __get_any_page() prints some messages about the page type in case the
page was a free page or the page type was unknown, but if anything, we
only need to print a message in case the pagetype was unknown, as that is
reporting an error down the chain.

Let us merge get_any_page() and __get_any_page(), and let the message be
printed in soft_offline_page.  While we are it, we can also remove the
'pfn' parameter as it is no longer used.

Link: https://lkml.kernel.org/r/20201204102558.31607-1-osalvador@suse.de
Link: https://lkml.kernel.org/r/20201204102558.31607-2-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Acked-by: Vlastimil Babka <Vbabka@suse.cz>
Cc: Qian Cai <qcai@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm,hwpoison: drop unneeded pcplist draining

memory_failure and soft_offline_path paths now drain pcplists by calling
get_hwpoison_page.

memory_failure flags the page as HWPoison before, so that page cannot
longer go into a pcplist, and soft_offline_page only flags a page as
HWPoison if 1) we took the page off a buddy freelist 2) the page was
in-use and we migrated it 3) was a clean pagecache.

Because of that, a page cannot longer be poisoned and be in a pcplist.

Link: https://lkml.kernel.org/r/20201013144447.6706-5-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm,hwpoison: take free pages off the buddy freelists

The crux of the matter is that historically we left poisoned pages in the
buddy system because we have some checks in place when allocating a page
that are gatekeeper for poisoned pages.  Unfortunately, we do have other
users (e.g: compaction [1]) that scan buddy freelists and try to get a
page from there without checking whether the page is HWPoison.

As I stated already, I think it is fundamentally wrong to keep HWPoison
pages within the buddy systems, checks in place or not.

Let us fix this the same way we did for soft_offline [2], taking the page
off the buddy freelist so it is completely unreachable.

Note that this is fairly simple to trigger, as we only need to poison free
buddy pages (madvise MADV_HWPOISON) and then run some sort of memory
stress system.

Just for a matter of reference, I put a dump_page() in compaction_alloc()
to trigger for HWPoison patches:

    page:0000000012b2982b refcount:1 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x1d5db
    flags: 0xfffffc0800000(hwpoison)
    raw: 000fffffc0800000 ffffea00007573c8 ffffc90000857de0 0000000000000000
    raw: 0000000000000001 0000000000000000 00000001ffffffff 0000000000000000
    page dumped because: compaction_alloc

    CPU: 4 PID: 123 Comm: kcompactd0 Tainted: G            E     5.9.0-rc2-mm1-1-default+ #5
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
    Call Trace:
     dump_stack+0x6d/0x8b
     compaction_alloc+0xb2/0xc0
     migrate_pages+0x2a6/0x12a0
     compact_zone+0x5eb/0x11c0
     proactive_compact_node+0x89/0xf0
     kcompactd+0x2d0/0x3a0
     kthread+0x118/0x130
     ret_from_fork+0x22/0x30

After that, if e.g: a process faults in the page,  it will get killed
unexpectedly.
Fix it by containing the page immediatelly.

Besides that, two more changes can be noticed:

* MF_DELAYED no longer suits as we are fixing the issue by containing
  the page immediately, so it does no longer rely on the allocation-time
  checks to stop HWPoison to be handed over.
  gain unless it is unpoisoned, so we fixed the situation.
  Because of that, let us use MF_RECOVERED from now on.

* The second block that handles PageBuddy pages is no longer needed:
  We call shake_page and then check whether the page is Buddy
  because shake_page calls drain_all_pages, which sends pcp-pages back to
  the buddy freelists, so we could have a chance to handle free pages.
  Currently, get_hwpoison_page already calls drain_all_pages, and we call
  get_hwpoison_page right before coming here, so we should be on the safe
  side.

[1] https://lore.kernel.org/linux-mm/20190826104144.GA7849@linux/T/#u
[2] https://patchwork.kernel.org/cover/11792607/

[osalvador@suse.de: take the poisoned subpage off the buddy frelists]
Link: https://lkml.kernel.org/r/20201013144447.6706-4-osalvador@suse.de
Link: https://lkml.kernel.org/r/20201013144447.6706-3-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm,hwpoison: drain pcplists before bailing out for non-buddy zero-refcount page

Patch series "HWpoison: further fixes and cleanups", v5.

This patchset includes some more fixes and a cleanup.

Patch#2 and patch#3 are both fixes for taking a HWpoison page off a buddy
freelist, since having them there has proved to be bad (see [1] and
pathch#2's commit log).  Patch#3 does the same for hugetlb pages.

[1] https://lkml.org/lkml/2020/9/22/565

This patch (of 4):

A page with 0-refcount and !PageBuddy could perfectly be a pcppage.
Currently, we bail out with an error if we encounter such a page, meaning
that we do not handle pcppages neither from hard-offline nor from
soft-offline path.

Fix this by draining pcplists whenever we find this kind of page and retry
the check again.  It might be that pcplists have been spilled into the
buddy allocator and so we can handle it.

Link: https://lkml.kernel.org/r/20201013144447.6706-1-osalvador@suse.de
Link: https://lkml.kernel.org/r/20201013144447.6706-2-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc: speed up the iteration of max_order

When we free a page whose order is very close to MAX_ORDER and greater
than pageblock_order, it wastes some CPU cycles to increase max_order to
MAX_ORDER one by one and check the pageblock migratetype of that page
repeatedly especially when MAX_ORDER is much larger than pageblock_order.

We also should not be checking migratetype of buddy when "order ==
MAX_ORDER - 1" as the buddy pfn may be invalid, so adjust the condition.
With the new check, we don't need the max_order check anymore, so we
replace it.

Also adjust max_order initialization so that it's lower by one than
previously, which makes the code hopefully more clear.

Link: https://lkml.kernel.org/r/20201204155109.55451-1-songmuchun@bytedance.com
Fixes: d9dddbf55667 ("mm/page_alloc: prevent merging between isolated and other pageblocks")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: page_alloc: refactor setup_per_zone_lowmem_reserve()

setup_per_zone_lowmem_reserve() iterates through each zone setting
zone->lowmem_reserve[j] = 0 (where j is the zone's index) then iterates
backwards through all preceding zones, setting
lower_zone->lowmem_reserve[j] = sum(managed pages of higher zones) /
lowmem_reserve_ratio[idx] for each (where idx is the lower zone's index).

If the lower zone has no managed pages or its ratio is 0 then all of its
lowmem_reserve[] entries are effectively zeroed.

As these arrays are only assigned here and all lowmem_reserve[] entries
for index < this zone's index are implicitly assumed to be 0 (as these are
specifically output in show_free_areas() and zoneinfo_show_print() for
example) there is no need to additionally zero index == this zone's index
too.  This patch avoids zeroing unnecessarily.

Rather than iterating through zones and setting lowmem_reserve[j] for each
lower zone this patch reverse the process and populates each zone's
lowmem_reserve[] values in ascending order.

This clarifies what is going on especially in the case of zero managed
pages or ratio which is now explicitly shown to clear these values.

Link: https://lkml.kernel.org/r/20201129162758.115907-1-lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main: fix broken buffer_init when DEFERRED_STRUCT_PAGE_INIT set

In the booting phase if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set,
we have following callchain:

start_kernel
...
  mm_init
    mem_init
     memblock_free_all
       reset_all_zones_managed_pages
       free_low_memory_core_early
...
  buffer_init
    nr_free_buffer_pages
      zone->managed_pages
...
  rest_init
    kernel_init
      kernel_init_freeable
        page_alloc_init_late
          kthread_run(deferred_init_memmap, NODE_DATA(nid), "pgdatinit%d", nid);
          wait_for_completion(&pgdat_init_all_done_comp);
          ...
          files_maxfiles_init

It's clear that buffer_init depends on zone->managed_pages, but it's reset
in reset_all_zones_managed_pages after that pages are readded into
zone->managed_pages, but when buffer_init runs this process is half done
and most of them will finally be added till deferred_init_memmap done.  In
large memory couting of nr_free_buffer_pages drifts too much, also
drifting from kernels to kernels on same hardware.

Fix is simple, it delays buffer_init run till deferred_init_memmap all
done.

But as corrected by this patch, max_buffer_heads becomes very large, the
value is roughly as many as 4 times of totalram_pages, formula:
max_buffer_heads = nrpages * (10%) * (PAGE_SIZE / sizeof(struct
buffer_head));

Say in a 64GB memory box we have 16777216 pages, then max_buffer_heads
turns out to be roughly 67,108,864.  In common cases, should a buffer_head
be mapped to one page/block(4KB)?  So max_buffer_heads never exceeds
totalram_pages.  IMO it's likely to make buffer_heads_over_limit bool
value alwasy false, then make codes 'if (buffer_heads_over_limit)' test in
vmscan unnecessary.

So this patch will change the original behavior related to
buffer_heads_over_limit in vmscan since we used a half done value of
zone->managed_pages before, or should we use a smaller factor(<10%) in
previous formula.

akpm: I think this is OK - the max_buffer_heads code is only needed on
highmem machines, to prevent ZONE_NORMAL from being consumed by large
amounts of buffer_heads attached to highmem pagecache.  This problem will
not occur on 64-bit machines, so this feature's non-functionality on such
machines is a feature, not a bug.

Link: https://lkml.kernel.org/r/20201123110500.103523-1-linf@wangsu.com
Signed-off-by: Lin Feng <linf@wangsu.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc: clear all pages in post_alloc_hook() with init_on_alloc=1

commit 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and
init_on_free=1 boot options") resulted with init_on_alloc=1 in all pages
leaving the buddy via alloc_pages() and friends to be
initialized/cleared/zeroed on allocation.

However, the same logic is currently not applied to alloc_contig_pages():
allocated pages leaving the buddy aren't cleared with init_on_alloc=1 and
init_on_free=0.  Let's also properly clear pages on that allocation path.

To achieve that, let's move clearing into post_alloc_hook().  This will
not only affect alloc_contig_pages() allocations but also any pages used
as migration target in compaction code via compaction_alloc().

While this sounds sub-optimal, it's the very same handling as when
allocating migration targets via alloc_migration_target() - pages will get
properly cleared with init_on_free=1.  In case we ever want to optimize
migration in that regard, we should tackle all such migration users - if
we believe migration code can be fully trusted.

With this change, we will see double clearing of pages in some cases.  One
example are gigantic pages (either allocated via CMA, or allocated
dynamically via alloc_contig_pages()) - which is the right thing to do
(and to be optimized outside of the buddy in the callers) as discussed in:
https://lkml.kernel.org/r/20201019182853.7467-1-gpiccoli@canonical.com

This change implies that with init_on_alloc=1

 - All CMA allocations will be cleared

 - Gigantic pages allocated via alloc_contig_pages() will be cleared

 - virtio-mem memory to be unplugged will be cleared. While this is
   suboptimal, it's similar to memory balloon drivers handling, where
   all pages to be inflated will get cleared as well.

 - Pages isolated for compaction will be cleared

Link: https://lkml.kernel.org/r/20201120180452.19071-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc: mark some symbols with static keyword

Fix the following sparse warnings:

  mm/page_alloc.c:3040:6: warning: symbol '__drain_all_pages' was not declared. Should it be static?
  mm/page_alloc.c:6349:6: warning: symbol '__zone_set_pageset_high_and_batch' was not declared. Should it be static?

Link: https://lkml.kernel.org/r/1605517365-65858-1-git-send-email-zou_wei@huawei.com
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc: add __free_pages() documentation

Provide some guidance towards when this might not be the right interface
to use.

Link: https://lkml.kernel.org/r/20201027025523.3235-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page-flags: fix comment

We haven't had 'dontuse' flags since 2002.  Replace this obsolete warning
with a hopefully more useful one.

Link: https://lkml.kernel.org/r/20201027025823.3704-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>