Dave Hansen [Thu, 2 Sep 2021 21:59:16 +0000 (14:59 -0700)]
mm/migrate: demote pages during reclaim
This is mostly derived from a patch from Yang Shi:
https://lore.kernel.org/linux-mm/
1560468577-101178-10-git-send-email-yang.shi@linux.alibaba.com/
Add code to the reclaim path (shrink_page_list()) to "demote" data to
another NUMA node instead of discarding the data. This always avoids the
cost of I/O needed to read the page back in and sometimes avoids the
writeout cost when the page is dirty.
A second pass through shrink_page_list() will be made if any demotions
fail. This essentially falls back to normal reclaim behavior in the case
that demotions fail. Previous versions of this patch may have simply
failed to reclaim pages which were eligible for demotion but were unable
to be demoted in practice.
For some cases, for example, MADV_PAGEOUT, the pages are always discarded
instead of demoted to follow the kernel API definition. Because
MADV_PAGEOUT is defined as freeing specified pages regardless in which
tier they are.
Note: This just adds the start of infrastructure for migration. It is
actually disabled next to the FIXME in migrate_demote_page_ok().
[dave.hansen@linux.intel.com: v11]
Link: https://lkml.kernel.org/r/20210715055145.195411-5-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210721063926.3024591-4-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-5-ying.huang@intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Wei Xu <weixugc@google.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yang Shi [Thu, 2 Sep 2021 21:59:13 +0000 (14:59 -0700)]
mm/migrate: enable returning precise migrate_pages() success count
Under normal circumstances, migrate_pages() returns the number of pages
migrated. In error conditions, it returns an error code. When returning
an error code, there is no way to know how many pages were migrated or not
migrated.
Make migrate_pages() return how many pages are demoted successfully for
all cases, including when encountering errors. Page reclaim behavior will
depend on this in subsequent patches.
Link: https://lkml.kernel.org/r/20210721063926.3024591-3-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-4-ying.huang@intel.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: Oscar Salvador <osalvador@suse.de> [optional parameter]
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dave Hansen [Thu, 2 Sep 2021 21:59:09 +0000 (14:59 -0700)]
mm/migrate: update node demotion order on hotplug events
Reclaim-based migration is attempting to optimize data placement in memory
based on the system topology. If the system changes, so must the
migration ordering.
The implementation is conceptually simple and entirely unoptimized. On
any memory or CPU hotplug events, assume that a node was added or removed
and recalculate all migration targets. This ensures that the
node_demotion[] array is always ready to be used in case the new reclaim
mode is enabled.
This recalculation is far from optimal, most glaringly that it does not
even attempt to figure out the hotplug event would have some *actual*
effect on the demotion order. But, given the expected paucity of hotplug
events, this should be fine.
Link: https://lkml.kernel.org/r/20210721063926.3024591-2-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-3-ying.huang@intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
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>
Dave Hansen [Thu, 2 Sep 2021 21:59:06 +0000 (14:59 -0700)]
mm/numa: automatically generate node migration order
Patch series "Migrate Pages in lieu of discard", v11.
We're starting to see systems with more and more kinds of memory such as
Intel's implementation of persistent memory.
Let's say you have a system with some DRAM and some persistent memory.
Today, once DRAM fills up, reclaim will start and some of the DRAM
contents will be thrown out. Allocations will, at some point, start
falling over to the slower persistent memory.
That has two nasty properties. First, the newer allocations can end up in
the slower persistent memory. Second, reclaimed data in DRAM are just
discarded even if there are gobs of space in persistent memory that could
be used.
This patchset implements a solution to these problems. At the end of the
reclaim process in shrink_page_list() just before the last page refcount
is dropped, the page is migrated to persistent memory instead of being
dropped.
While I've talked about a DRAM/PMEM pairing, this approach would function
in any environment where memory tiers exist.
This is not perfect. It "strands" pages in slower memory and never brings
them back to fast DRAM. Huang Ying has follow-on work which repurposes
NUMA balancing to promote hot pages back to DRAM.
This is also all based on an upstream mechanism that allows persistent
memory to be onlined and used as if it were volatile:
http://lkml.kernel.org/r/
20190124231441.
37A4A305@viggo.jf.intel.com
With that, the DRAM and PMEM in each socket will be represented as 2
separate NUMA nodes, with the CPUs sit in the DRAM node. So the
general inter-NUMA demotion mechanism introduced in the patchset can
migrate the cold DRAM pages to the PMEM node.
We have tested the patchset with the postgresql and pgbench. On a
2-socket server machine with DRAM and PMEM, the kernel with the patchset
can improve the score of pgbench up to 22.1% compared with that of the
DRAM only + disk case. This comes from the reduced disk read throughput
(which reduces up to 70.8%).
== Open Issues ==
* Memory policies and cpusets that, for instance, restrict allocations
to DRAM can be demoted to PMEM whenever they opt in to this
new mechanism. A cgroup-level API to opt-in or opt-out of
these migrations will likely be required as a follow-on.
* Could be more aggressive about where anon LRU scanning occurs
since it no longer necessarily involves I/O. get_scan_count()
for instance says: "If we have no swap space, do not bother
scanning anon pages"
This patch (of 9):
Prepare for the kernel to auto-migrate pages to other memory nodes with a
node migration table. This allows creating single migration target for
each NUMA node to enable the kernel to do NUMA page migrations instead of
simply discarding colder pages. A node with no target is a "terminal
node", so reclaim acts normally there. The migration target does not
fundamentally _need_ to be a single node, but this implementation starts
there to limit complexity.
When memory fills up on a node, memory contents can be automatically
migrated to another node. The biggest problems are knowing when to
migrate and to where the migration should be targeted.
The most straightforward way to generate the "to where" list would be to
follow the page allocator fallback lists. Those lists already tell us if
memory is full where to look next. It would also be logical to move
memory in that order.
But, the allocator fallback lists have a fatal flaw: most nodes appear in
all the lists. This would potentially lead to migration cycles (A->B,
B->A, A->B, ...).
Instead of using the allocator fallback lists directly, keep a separate
node migration ordering. But, reuse the same data used to generate page
allocator fallback in the first place: find_next_best_node().
This means that the firmware data used to populate node distances
essentially dictates the ordering for now. It should also be
architecture-neutral since all NUMA architectures have a working
find_next_best_node().
RCU is used to allow lock-less read of node_demotion[] and prevent
demotion cycles been observed. If multiple reads of node_demotion[] are
performed, a single rcu_read_lock() must be held over all reads to ensure
no cycles are observed. Details are as follows.
=== What does RCU provide? ===
Imagine a simple loop which walks down the demotion path looking
for the last node:
terminal_node = start_node;
while (node_demotion[terminal_node] != NUMA_NO_NODE) {
terminal_node = node_demotion[terminal_node];
}
The initial values are:
node_demotion[0] = 1;
node_demotion[1] = NUMA_NO_NODE;
and are updated to:
node_demotion[0] = NUMA_NO_NODE;
node_demotion[1] = 0;
What guarantees that the cycle is not observed:
node_demotion[0] = 1;
node_demotion[1] = 0;
and would loop forever?
With RCU, a rcu_read_lock/unlock() can be placed around the loop. Since
the write side does a synchronize_rcu(), the loop that observed the old
contents is known to be complete before the synchronize_rcu() has
completed.
RCU, combined with disable_all_migrate_targets(), ensures that the old
migration state is not visible by the time __set_migration_target_nodes()
is called.
=== What does READ_ONCE() provide? ===
READ_ONCE() forbids the compiler from merging or reordering successive
reads of node_demotion[]. This ensures that any updates are *eventually*
observed.
Consider the above loop again. The compiler could theoretically read the
entirety of node_demotion[] into local storage (registers) and never go
back to memory, and *permanently* observe bad values for node_demotion[].
Note: RCU does not provide any universal compiler-ordering
guarantees:
https://lore.kernel.org/lkml/
20150921204327.GH4029@linux.vnet.ibm.com/
This code is unused for now. It will be called later in the
series.
Link: https://lkml.kernel.org/r/20210721063926.3024591-1-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-1-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-2-ying.huang@intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
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>
Nadav Amit [Thu, 2 Sep 2021 21:59:02 +0000 (14:59 -0700)]
selftests/vm/userfaultfd: wake after copy failure
When userfaultfd copy-ioctl fails since the PTE already exists, an -EEXIST
error is returned and the faulting thread is not woken. The current
userfaultfd test does not wake the faulting thread in such case. The
assumption is presumably that another thread set the PTE through copy/wp
ioctl and would wake the faulting thread or that alternatively the fault
handler would realize there is no need to "must_wait" and continue. This
is not necessarily true.
There is an assumption that the "must_wait" tests in handle_userfault()
are sufficient to provide definitive answer whether the offending PTE is
populated or not. However, userfaultfd_must_wait() test is lockless.
Consequently, concurrent calls to ptep_modify_prot_start(), for instance,
can clear the PTE and can cause userfaultfd_must_wait() to wrongly assume
it is not populated and a wait is needed.
There are therefore 3 options:
(1) Change the tests to wake on copy failure.
(2) Wake faulting thread unconditionally on zero/copy ioctls before
returning -EEXIST.
(3) Change the userfaultfd_must_wait() to hold locks.
This patch took the first approach, but the others are valid solutions
with different tradeoffs.
Link: https://lkml.kernel.org/r/20210808020724.1022515-4-namit@vmware.com
Signed-off-by: Nadav Amit <namit@vmware.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Axel Rasmussen <axelrasmussen@google.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>
Nadav Amit [Thu, 2 Sep 2021 21:58:59 +0000 (14:58 -0700)]
userfaultfd: prevent concurrent API initialization
userfaultfd assumes that the enabled features are set once and never
changed after UFFDIO_API ioctl succeeded.
However, currently, UFFDIO_API can be called concurrently from two
different threads, succeed on both threads and leave userfaultfd's
features in non-deterministic state. Theoretically, other uffd operations
(ioctl's and page-faults) can be dispatched while adversely affected by
such changes of features.
Moreover, the writes to ctx->state and ctx->features are not ordered,
which can - theoretically, again - let userfaultfd_ioctl() think that
userfaultfd API completed, while the features are still not initialized.
To avoid races, it is arguably best to get rid of ctx->state. Since there
are only 2 states, record the API initialization in ctx->features as the
uppermost bit and remove ctx->state.
Link: https://lkml.kernel.org/r/20210808020724.1022515-3-namit@vmware.com
Fixes:
9cd75c3cd4c3d ("userfaultfd: non-cooperative: add ability to report non-PF events from uffd descriptor")
Signed-off-by: Nadav Amit <namit@vmware.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nadav Amit [Thu, 2 Sep 2021 21:58:56 +0000 (14:58 -0700)]
userfaultfd: change mmap_changing to atomic
Patch series "userfaultfd: minor bug fixes".
Three unrelated bug fixes. The first two addresses possible issues (not
too theoretical ones), but I did not encounter them in practice.
The third patch addresses a test bug that causes the test to fail on my
system. It has been sent before as part of a bigger RFC.
This patch (of 3):
mmap_changing is currently a boolean variable, which is set and cleared
without any lock that protects against concurrent modifications.
mmap_changing is supposed to mark whether userfaultfd page-faults handling
should be retried since mappings are undergoing a change. However,
concurrent calls, for instance to madvise(MADV_DONTNEED), might cause
mmap_changing to be false, although the remove event was still not read
(hence acknowledged) by the user.
Change mmap_changing to atomic_t and increase/decrease appropriately. Add
a debug assertion to see whether mmap_changing is negative.
Link: https://lkml.kernel.org/r/20210808020724.1022515-1-namit@vmware.com
Link: https://lkml.kernel.org/r/20210808020724.1022515-2-namit@vmware.com
Fixes:
df2cc96e77011 ("userfaultfd: prevent non-cooperative events vs mcopy_atomic races")
Signed-off-by: Nadav Amit <namit@vmware.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Kravetz [Thu, 2 Sep 2021 21:58:53 +0000 (14:58 -0700)]
hugetlb: fix hugetlb cgroup refcounting during vma split
Guillaume Morin reported hitting the following WARNING followed by GPF or
NULL pointer deference either in cgroups_destroy or in the kill_css path.:
percpu ref (css_release) <= 0 (-1) after switching to atomic
WARNING: CPU: 23 PID: 130 at lib/percpu-refcount.c:196 percpu_ref_switch_to_atomic_rcu+0x127/0x130
CPU: 23 PID: 130 Comm: ksoftirqd/23 Kdump: loaded Tainted: G O 5.10.60 #1
RIP: 0010:percpu_ref_switch_to_atomic_rcu+0x127/0x130
Call Trace:
rcu_core+0x30f/0x530
rcu_core_si+0xe/0x10
__do_softirq+0x103/0x2a2
run_ksoftirqd+0x2b/0x40
smpboot_thread_fn+0x11a/0x170
kthread+0x10a/0x140
ret_from_fork+0x22/0x30
Upon further examination, it was discovered that the css structure was
associated with hugetlb reservations.
For private hugetlb mappings the vma points to a reserve map that
contains a pointer to the css. At mmap time, reservations are set up
and a reference to the css is taken. This reference is dropped in the
vma close operation; hugetlb_vm_op_close. However, if a vma is split no
additional reference to the css is taken yet hugetlb_vm_op_close will be
called twice for the split vma resulting in an underflow.
Fix by taking another reference in hugetlb_vm_op_open. Note that the
reference is only taken for the owner of the reserve map. In the more
common fork case, the pointer to the reserve map is cleared for
non-owning vmas.
Link: https://lkml.kernel.org/r/20210830215015.155224-1-mike.kravetz@oracle.com
Fixes:
e9fe92ae0cd2 ("hugetlb_cgroup: add reservation accounting for private mappings")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Guillaume Morin <guillaume@morinfr.org>
Suggested-by: Guillaume Morin <guillaume@morinfr.org>
Tested-by: Guillaume Morin <guillaume@morinfr.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Kravetz [Thu, 2 Sep 2021 21:58:50 +0000 (14:58 -0700)]
hugetlb: before freeing hugetlb page set dtor to appropriate value
When removing a hugetlb page from the pool the ref count is set to one (as
the free page has no ref count) and compound page destructor is set to
NULL_COMPOUND_DTOR. Since a subsequent call to free the hugetlb page will
call __free_pages for non-gigantic pages and free_gigantic_page for
gigantic pages the destructor is not used.
However, consider the following race with code taking a speculative
reference on the page:
Thread 0 Thread 1
-------- --------
remove_hugetlb_page
set_page_refcounted(page);
set_compound_page_dtor(page,
NULL_COMPOUND_DTOR);
get_page_unless_zero(page)
__update_and_free_page
__free_pages(page,
huge_page_order(h));
/* Note that __free_pages() will simply drop
the reference to the page. */
put_page(page)
__put_compound_page()
destroy_compound_page
NULL_COMPOUND_DTOR
BUG: kernel NULL pointer
dereference, address:
0000000000000000
To address this race, set the dtor to the normal compound page dtor for
non-gigantic pages. The dtor for gigantic pages does not matter as
gigantic pages are changed from a compound page to 'just a group of pages'
before freeing. Hence, the destructor is not used.
Link: https://lkml.kernel.org/r/20210809184832.18342-4-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Mina Almasry <almasrymina@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Kravetz [Thu, 2 Sep 2021 21:58:47 +0000 (14:58 -0700)]
hugetlb: drop ref count earlier after page allocation
When discussing the possibility of inflated page ref counts, Muuchun Song
pointed out this potential issue [1]. It is true that any code could
potentially take a reference on a compound page after allocation and
before it is converted to and put into use as a hugetlb page.
Specifically, this could be done by any users of get_page_unless_zero.
There are three areas of concern within hugetlb code.
1) When adding pages to the pool. In this case, new pages are
allocated added to the pool by calling put_page to invoke the hugetlb
destructor (free_huge_page). If there is an inflated ref count on the
page, it will not be immediately added to the free list. It will only
be added to the free list when the temporary ref count is dropped.
This is deemed acceptable and will not be addressed.
2) A page is allocated for immediate use normally as a surplus page or
migration target. In this case, the user of the page will also hold a
reference. There is no issue as this is just like normal page ref
counting.
3) A page is allocated and MUST be added to the free list to satisfy a
reservation. One such example is gather_surplus_pages as pointed out
by Muchun in [1]. More specifically, this case covers callers of
enqueue_huge_page where the page reference count must be zero. This
patch covers this third case.
Three routines call enqueue_huge_page when the page reference count could
potentially be inflated. They are: gather_surplus_pages,
alloc_and_dissolve_huge_page and add_hugetlb_page.
add_hugetlb_page is called on error paths when a huge page can not be
freed due to the inability to allocate vmemmap pages. In this case, the
temporairly inflated ref count is not an issue. When the ref is dropped
the appropriate action will be taken. Instead of VM_BUG_ON if the ref
count does not drop to zero, simply return.
In gather_surplus_pages and alloc_and_dissolve_huge_page the caller
expects a page (or pages) to be put on the free lists. In this case we
must ensure there are no temporary ref counts. We do this by calling
put_page_testzero() earlier and not using pages without a zero ref count.
The temporary page flag (HPageTemporary) is used in such cases so that as
soon as the inflated ref count is dropped the page will be freed.
[1] https://lore.kernel.org/linux-mm/CAMZfGtVMn3daKrJwZMaVOGOaJU+B4dS--x_oPmGQMD=c=QNGEg@mail.gmail.com/
Link: https://lkml.kernel.org/r/20210809184832.18342-3-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Kravetz [Thu, 2 Sep 2021 21:58:43 +0000 (14:58 -0700)]
hugetlb: simplify prep_compound_gigantic_page ref count racing code
Code in prep_compound_gigantic_page waits for a rcu grace period if it
notices a temporarily inflated ref count on a tail page. This was due to
the identified potential race with speculative page cache references which
could only last for a rcu grace period. This is overly complicated as
this situation is VERY unlikely to ever happen. Instead, just quickly
return an error.
Also, only print a warning in prep_compound_gigantic_page instead of
multiple callers.
Link: https://lkml.kernel.org/r/20210809184832.18342-2-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michael Wang [Thu, 2 Sep 2021 21:58:40 +0000 (14:58 -0700)]
mm: fix panic caused by __page_handle_poison()
In commit
510d25c92ec4 ("mm/hwpoison: disable pcp for
page_handle_poison()"), __page_handle_poison() was introduced, and if we
mark:
RET_A = dissolve_free_huge_page();
RET_B = take_page_off_buddy();
then __page_handle_poison was supposed to return TRUE When RET_A == 0 &&
RET_B == TRUE
But since it failed to take care the case when RET_A is -EBUSY or -ENOMEM,
and just return the ret as a bool which actually become TRUE, it break the
original logic.
The following result is a huge page in freelist but was
referenced as poisoned, and lead into the final panic:
kernel BUG at mm/internal.h:95!
invalid opcode: 0000 [#1] SMP PTI
skip...
RIP: 0010:set_page_refcounted mm/internal.h:95 [inline]
RIP: 0010:remove_hugetlb_page+0x23c/0x240 mm/hugetlb.c:1371
skip...
Call Trace:
remove_pool_huge_page+0xe4/0x110 mm/hugetlb.c:1892
return_unused_surplus_pages+0x8d/0x150 mm/hugetlb.c:2272
hugetlb_acct_memory.part.91+0x524/0x690 mm/hugetlb.c:4017
This patch replaces 'bool' with 'int' to handle RET_A correctly.
Link: https://lkml.kernel.org/r/61782ac6-1e8a-4f6f-35e6-e94fce3b37f5@linux.alibaba.com
Fixes:
510d25c92ec4 ("mm/hwpoison: disable pcp for page_handle_poison()")
Signed-off-by: Michael Wang <yun.wang@linux.alibaba.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: Abaci <abaci@linux.alibaba.com>
Cc: <stable@vger.kernel.org> [5.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yang Shi [Thu, 2 Sep 2021 21:58:37 +0000 (14:58 -0700)]
mm: hwpoison: dump page for unhandlable page
Currently just very simple message is shown for unhandlable page, e.g.
non-LRU page, like: soft_offline: 0x1469f2: unknown non LRU page type
5ffff0000000000 ()
It is not very helpful for further debug, calling dump_page() could show
more useful information.
Calling dump_page() in get_any_page() in order to not duplicate the call
in a couple of different places. It may be called with pcp disabled and
holding memory hotplug lock, it should be not a big deal since hwpoison
handler is not called very often.
[shy828301@gmail.com: remove redundant pr_info per Noaya Horiguchi]
Link: https://lkml.kernel.org/r/20210824020946.195257-3-shy828301@gmail.com
Link: https://lkml.kernel.org/r/20210819054116.266126-3-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Mackey <tdmackey@twitter.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yang Shi [Thu, 2 Sep 2021 21:58:34 +0000 (14:58 -0700)]
doc: hwpoison: correct the support for hugepage
The hwpoison support for huge page, both hugetlb and THP, has been in
kernel for a while, the statement in document is obsolete, correct it.
Link: https://lkml.kernel.org/r/20210819054116.266126-2-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Mackey <tdmackey@twitter.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yang Shi [Thu, 2 Sep 2021 21:58:31 +0000 (14:58 -0700)]
mm: hwpoison: don't drop slab caches for offlining non-LRU page
In the current implementation of soft offline, if non-LRU page is met,
all the slab caches will be dropped to free the page then offline. But
if the page is not slab page all the effort is wasted in vain. Even
though it is a slab page, it is not guaranteed the page could be freed
at all.
However the side effect and cost is quite high. It does not only drop
the slab caches, but also may drop a significant amount of page caches
which are associated with inode caches. It could make the most
workingset gone in order to just offline a page. And the offline is not
guaranteed to succeed at all, actually I really doubt the success rate
for real life workload.
Furthermore the worse consequence is the system may be locked up and
unusable since the page cache release may incur huge amount of works
queued for memcg release.
Actually we ran into such unpleasant case in our production environment.
Firstly, the workqueue of memory_failure_work_func is locked up as
below:
BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 53s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=14/256 refcnt=15
in-flight: 409271:memory_failure_work_func
pending: kfree_rcu_work, kfree_rcu_monitor, kfree_rcu_work, rht_deferred_worker, rht_deferred_worker, rht_deferred_worker, rht_deferred_worker, kfree_rcu_work, kfree_rcu_work, kfree_rcu_work, kfree_rcu_work, drain_local_stock, kfree_rcu_work
workqueue mm_percpu_wq: flags=0x8
pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
pending: vmstat_update
workqueue cgroup_destroy: flags=0x0
pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 refcnt=12072
pending: css_release_work_fn
There were over 12K css_release_work_fn queued, and this caused a few
lockups due to the contention of worker pool lock with IRQ disabled, for
example:
NMI watchdog: Watchdog detected hard LOCKUP on cpu 1
Modules linked in: amd64_edac_mod edac_mce_amd crct10dif_pclmul crc32_pclmul ghash_clmulni_intel xt_DSCP iptable_mangle kvm_amd bpfilter vfat fat acpi_ipmi i2c_piix4 usb_storage ipmi_si k10temp i2c_core ipmi_devintf ipmi_msghandler acpi_cpufreq sch_fq_codel xfs libcrc32c crc32c_intel mlx5_core mlxfw nvme xhci_pci ptp nvme_core pps_core xhci_hcd
CPU: 1 PID: 205500 Comm: kworker/1:0 Tainted: G L 5.10.32-t1.el7.twitter.x86_64 #1
Hardware name: TYAN F5AMT /z /S8026GM2NRE-CGN, BIOS V8.030 03/30/2021
Workqueue: events memory_failure_work_func
RIP: 0010:queued_spin_lock_slowpath+0x41/0x1a0
Code: 41 f0 0f ba 2f 08 0f 92 c0 0f b6 c0 c1 e0 08 89 c2 8b 07 30 e4 09 d0 a9 00 01 ff ff 75 1b 85 c0 74 0e 8b 07 84 c0 74 08 f3 90 <8b> 07 84 c0 75 f8 b8 01 00 00 00 66 89 07 c3 f6 c4 01 75 04 c6 47
RSP: 0018:
ffff9b2ac278f900 EFLAGS:
00000002
RAX:
0000000000480101 RBX:
ffff8ce98ce71800 RCX:
0000000000000084
RDX:
0000000000000000 RSI:
0000000000000000 RDI:
ffff8ce98ce6a140
RBP:
00000000000284c8 R08:
ffffd7248dcb6808 R09:
0000000000000000
R10:
0000000000000003 R11:
ffff9b2ac278f9b0 R12:
0000000000000001
R13:
ffff8cb44dab9c00 R14:
ffffffffbd1ce6a0 R15:
ffff8cacaa37f068
FS:
0000000000000000(0000) GS:
ffff8ce98ce40000(0000) knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
00007fcf6e8cb000 CR3:
0000000a0c60a000 CR4:
0000000000350ee0
Call Trace:
__queue_work+0xd6/0x3c0
queue_work_on+0x1c/0x30
uncharge_batch+0x10e/0x110
mem_cgroup_uncharge_list+0x6d/0x80
release_pages+0x37f/0x3f0
__pagevec_release+0x1c/0x50
__invalidate_mapping_pages+0x348/0x380
inode_lru_isolate+0x10a/0x160
__list_lru_walk_one+0x7b/0x170
list_lru_walk_one+0x4a/0x60
prune_icache_sb+0x37/0x50
super_cache_scan+0x123/0x1a0
do_shrink_slab+0x10c/0x2c0
shrink_slab+0x1f1/0x290
drop_slab_node+0x4d/0x70
soft_offline_page+0x1ac/0x5b0
memory_failure_work_func+0x6a/0x90
process_one_work+0x19e/0x340
worker_thread+0x30/0x360
kthread+0x116/0x130
The lockup made the machine is quite unusable. And it also made the
most workingset gone, the reclaimabled slab caches were reduced from 12G
to 300MB, the page caches were decreased from 17G to 4G.
But the most disappointing thing is all the effort doesn't make the page
offline, it just returns:
soft_offline: 0x1469f2: unknown non LRU page type
5ffff0000000000 ()
It seems the aggressive behavior for non-LRU page didn't pay back, so it
doesn't make too much sense to keep it considering the terrible side
effect.
Link: https://lkml.kernel.org/r/20210819054116.266126-1-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reported-by: David Mackey <tdmackey@twitter.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox (Oracle) <willy@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>
Miaohe Lin [Thu, 2 Sep 2021 21:58:28 +0000 (14:58 -0700)]
mm/hwpoison: fix some obsolete comments
Since commit
cb731d6c62bb ("vmscan: per memory cgroup slab shrinkers"),
shrink_node_slabs is renamed to drop_slab_node. And doit argument is
changed to forcekill since commit
6751ed65dc66 ("x86/mce: Fix
siginfo_t->si_addr value for non-recoverable memory faults").
Link: https://lkml.kernel.org/r/20210814105131.48814-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
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>
Miaohe Lin [Thu, 2 Sep 2021 21:58:25 +0000 (14:58 -0700)]
mm/hwpoison: change argument struct page **hpagep to *hpage
It's unnecessary to pass in a struct page **hpagep because it's never
modified. Changing to use *hpage to simplify the code.
Link: https://lkml.kernel.org/r/20210814105131.48814-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
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>
Miaohe Lin [Thu, 2 Sep 2021 21:58:22 +0000 (14:58 -0700)]
mm/hwpoison: fix potential pte_unmap_unlock pte error
If the first pte is equal to poisoned_pfn, i.e. check_hwpoisoned_entry()
return 1, the wrong ptep - 1 would be passed to pte_unmap_unlock().
Link: https://lkml.kernel.org/r/20210814105131.48814-3-linmiaohe@huawei.com
Fixes:
ad9c59c24095 ("mm,hwpoison: send SIGBUS with error virutal address")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
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>
Miaohe Lin [Thu, 2 Sep 2021 21:58:19 +0000 (14:58 -0700)]
mm/hwpoison: remove unneeded variable unmap_success
Patch series "Cleanups and fixup for hwpoison"
This series contains cleanups to remove unneeded variable, fix some
obsolete comments and so on. Also we fix potential pte_unmap_unlock on
wrong pte. More details can be found in the respective changelogs.
This patch (of 4):
unmap_success is used to indicate whether page is successfully unmapped
but it's irrelated with ZONE_DEVICE page and unmap_success is always true
here. Remove this unneeded one.
Link: https://lkml.kernel.org/r/20210814105131.48814-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210814105131.48814-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
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>
George G. Davis [Thu, 2 Sep 2021 21:58:16 +0000 (14:58 -0700)]
mm/page_isolation: tracing: trace all test_pages_isolated failures
Some test_pages_isolated failure conditions don't include trace points.
For debugging issues caused by "pinned" pages, make sure to trace all
calls whether they succeed or fail. In this case, a failure case did not
result in a trace point. So add the missing failure case in
test_pages_isolated traces.
Link: https://lkml.kernel.org/r/20210823202823.13765-1-george_davis@mentor.com
Signed-off-by: George G. Davis <davis.george@siemens.com>
Cc: Eugeniu Rosca <erosca@de.adit-jv.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Thu, 2 Sep 2021 21:58:13 +0000 (14:58 -0700)]
mm/page_alloc.c: use in_task()
Obsoleted in_intrrupt() include task context with disabled BH, it's better
to use in_task() instead.
Link: https://lkml.kernel.org/r/877caa99-1994-5545-92d2-d0bb2e394182@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Thu, 2 Sep 2021 21:58:10 +0000 (14:58 -0700)]
mm/page_alloc: make alloc_node_mem_map() __init rather than __ref
alloc_node_mem_map() is never only called from free_area_init_node() that
is an __init function.
Make the actual alloc_node_mem_map() also __init and its stub version
static inline.
Link: https://lkml.kernel.org/r/20210716064124.31865-1-rppt@kernel.org
Signed-off-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>
Nico Pache [Thu, 2 Sep 2021 21:58:08 +0000 (14:58 -0700)]
mm/page_alloc.c: fix 'zone_id' may be used uninitialized in this function warning
When compiling with -Werror, cc1 will warn that 'zone_id' may be used
uninitialized in this function warning.
Initialize the zone_id as 0.
Its safe to assume that if the code reaches this point it has at least one
numa node with memory, so no need for an assertion before
init_unavilable_range.
Link: https://lkml.kernel.org/r/20210716210336.1114114-1-npache@redhat.com
Fixes:
122e093c1734 ("mm/page_alloc: fix memory map initialization for descending nodes")
Signed-off-by: Nico Pache <npache@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Thu, 2 Sep 2021 21:58:05 +0000 (14:58 -0700)]
memblock: stop poisoning raw allocations
Functions memblock_alloc_exact_nid_raw() and memblock_alloc_try_nid_raw()
are intended for early memory allocation without overhead of zeroing the
allocated memory. Since these functions were used to allocate the memory
map, they have ended up with addition of a call to page_init_poison() that
poisoned the allocated memory when CONFIG_PAGE_POISON was set.
Since the memory map is allocated using a dedicated memmep_alloc()
function that takes care of the poisoning, remove page poisoning from the
memblock_alloc_*_raw() functions.
Link: https://lkml.kernel.org/r/20210714123739.16493-5-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Thu, 2 Sep 2021 21:58:02 +0000 (14:58 -0700)]
mm: introduce memmap_alloc() to unify memory map allocation
There are several places that allocate memory for the memory map:
alloc_node_mem_map() for FLATMEM, sparse_buffer_init() and
__populate_section_memmap() for SPARSEMEM.
The memory allocated in the FLATMEM case is zeroed and it is never
poisoned, regardless of CONFIG_PAGE_POISON setting.
The memory allocated in the SPARSEMEM cases is not zeroed and it is
implicitly poisoned inside memblock if CONFIG_PAGE_POISON is set.
Introduce memmap_alloc() wrapper for memblock allocators that will be used
for both FLATMEM and SPARSEMEM cases and will makei memory map zeroing and
poisoning consistent for different memory models.
Link: https://lkml.kernel.org/r/20210714123739.16493-4-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Thu, 2 Sep 2021 21:57:59 +0000 (14:57 -0700)]
microblaze: simplify pte_alloc_one_kernel()
The microblaze's implementation of pte_alloc_one_kernel() used
memblock_alloc_try_nid_raw() along with clear_page() to allocated a zeroed
page during early setup.
Replace calls of these functions with a call to memblock_alloc_try_nid()
that already returns zeroed page and respects the same allocation limits
as memblock_alloc_try_nid_raw().
While on it drop early_get_page() wrapper that was only used in
pte_alloc_one_kernel().
Link: https://lkml.kernel.org/r/20210714123739.16493-3-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport [Thu, 2 Sep 2021 21:57:56 +0000 (14:57 -0700)]
mm/page_alloc: always initialize memory map for the holes
Patch series "mm: ensure consistency of memory map poisoning".
Currently memory map allocation for FLATMEM case does not poison the
struct pages regardless of CONFIG_PAGE_POISON setting.
This happens because allocation of the memory map for FLATMEM and SPARSMEM
use different memblock functions and those that are used for SPARSMEM case
(namely memblock_alloc_try_nid_raw() and memblock_alloc_exact_nid_raw())
implicitly poison the allocated memory.
Another side effect of this implicit poisoning is that early setup code
that uses the same functions to allocate memory burns cycles for the
memory poisoning even if it was not intended.
These patches introduce memmap_alloc() wrapper that ensure that the memory
map allocation is consistent for different memory models.
This patch (of 4):
Currently memory map for the holes is initialized only when SPARSEMEM
memory model is used. Yet, even with FLATMEM there could be holes in the
physical memory layout that have memory map entries.
For instance, the memory reserved using e820 API on i386 or
"reserved-memory" nodes in device tree would not appear in memblock.memory
and hence the struct pages for such holes will be skipped during memory
map initialization.
These struct pages will be zeroed because the memory map for FLATMEM
systems is allocated with memblock_alloc_node() that clears the allocated
memory. While zeroed struct pages do not cause immediate problems, the
correct behaviour is to initialize every page using __init_single_page().
Besides, enabling page poison for FLATMEM case will trigger
PF_POISONED_CHECK() unless the memory map is properly initialized.
Make sure init_unavailable_range() is called for both SPARSEMEM and
FLATMEM so that struct pages representing memory holes would appear as
PG_Reserved with any memory layout.
[rppt@kernel.org: fix microblaze]
Link: https://lkml.kernel.org/r/YQWW3RCE4eWBuMu/@kernel.org
Link: https://lkml.kernel.org/r/20210714123739.16493-1-rppt@kernel.org
Link: https://lkml.kernel.org/r/20210714123739.16493-2-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: Michal Simek <monstr@monstr.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Thu, 2 Sep 2021 21:57:53 +0000 (14:57 -0700)]
kasan: test: avoid corrupting memory in kasan_rcu_uaf
kasan_rcu_uaf() writes to freed memory via kasan_rcu_reclaim(), which is
only safe with the GENERIC mode (as it uses quarantine). For other modes,
this test corrupts kernel memory, which might result in a crash.
Turn the write into a read.
Link: https://lkml.kernel.org/r/b6f2c3bf712d2457c783fa59498225b66a634f62.1628779805.git.andreyknvl@gmail.com
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Thu, 2 Sep 2021 21:57:50 +0000 (14:57 -0700)]
kasan: test: avoid corrupting memory in copy_user_test
copy_user_test() does writes past the allocated object. As the result, it
corrupts kernel memory, which might lead to crashes with the HW_TAGS mode,
as it neither uses quarantine nor redzones.
(Technically, this test can't yet be enabled with the HW_TAGS mode, but
this will be implemented in the future.)
Adjust the test to only write memory within the aligned kmalloc object.
Link: https://lkml.kernel.org/r/19bf3a5112ee65b7db88dc731643b657b816c5e8.1628779805.git.andreyknvl@gmail.com
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Thu, 2 Sep 2021 21:57:47 +0000 (14:57 -0700)]
kasan: test: clean up ksize_uaf
Some KASAN tests use global variables to store function returns values so
that the compiler doesn't optimize away these functions.
ksize_uaf() doesn't call any functions, so it doesn't need to use
kasan_int_result. Use volatile accesses instead, to be consistent with
other similar tests.
Link: https://lkml.kernel.org/r/a1fc34faca4650f4a6e4dfb3f8d8d82c82eb953a.1628779805.git.andreyknvl@gmail.com
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Thu, 2 Sep 2021 21:57:44 +0000 (14:57 -0700)]
kasan: test: only do kmalloc_uaf_memset for generic mode
kmalloc_uaf_memset() writes to freed memory, which is only safe with the
GENERIC mode (as it uses quarantine). For other modes, this test corrupts
kernel memory, which might result in a crash.
Only enable kmalloc_uaf_memset() for the GENERIC mode.
Link: https://lkml.kernel.org/r/2e1c87b607b1292556cde3cab2764f108542b60c.1628779805.git.andreyknvl@gmail.com
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Thu, 2 Sep 2021 21:57:41 +0000 (14:57 -0700)]
kasan: test: disable kmalloc_memmove_invalid_size for HW_TAGS
The HW_TAGS mode doesn't check memmove for negative size. As a result,
the kmalloc_memmove_invalid_size test corrupts memory, which can result in
a crash.
Disable this test with HW_TAGS KASAN.
Link: https://lkml.kernel.org/r/088733a06ac21eba29aa85b6f769d2abd74f9638.1628779805.git.andreyknvl@gmail.com
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Thu, 2 Sep 2021 21:57:38 +0000 (14:57 -0700)]
kasan: test: avoid corrupting memory via memset
kmalloc_oob_memset_*() tests do writes past the allocated objects. As the
result, they corrupt memory, which might lead to crashes with the HW_TAGS
mode, as it neither uses quarantine nor redzones.
Adjust the tests to only write memory within the aligned kmalloc objects.
Also add a comment mentioning that memset tests are designed to touch both
valid and invalid memory.
Link: https://lkml.kernel.org/r/64fd457668a16e7b58d094f14a165f9d5170c5a9.1628779805.git.andreyknvl@gmail.com
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Thu, 2 Sep 2021 21:57:35 +0000 (14:57 -0700)]
kasan: test: avoid writing invalid memory
Multiple KASAN tests do writes past the allocated objects or writes to
freed memory. Turn these writes into reads to avoid corrupting memory.
Otherwise, these tests might lead to crashes with the HW_TAGS mode, as it
neither uses quarantine nor redzones.
Link: https://lkml.kernel.org/r/c3cd2a383e757e27dd9131635fc7d09a48a49cf9.1628779805.git.andreyknvl@gmail.com
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Thu, 2 Sep 2021 21:57:32 +0000 (14:57 -0700)]
kasan: test: rework kmalloc_oob_right
Patch series "kasan: test: avoid crashing the kernel with HW_TAGS", v2.
KASAN tests do out-of-bounds and use-after-free accesses. Running the
tests works fine for the GENERIC mode, as it uses qurantine and redzones.
But the HW_TAGS mode uses neither, and running the tests might crash the
kernel.
Rework the tests to avoid corrupting kernel memory.
This patch (of 8):
Rework kmalloc_oob_right() to do these bad access checks:
1. An unaligned access one byte past the requested kmalloc size
(can only be detected by KASAN_GENERIC).
2. An aligned access into the first out-of-bounds granule that falls
within the aligned kmalloc object.
3. Out-of-bounds access past the aligned kmalloc object.
Test #3 deliberately uses a read access to avoid corrupting memory.
Otherwise, this test might lead to crashes with the HW_TAGS mode, as it
neither uses quarantine nor redzones.
Link: https://lkml.kernel.org/r/cover.1628779805.git.andreyknvl@gmail.com
Link: https://lkml.kernel.org/r/474aa8b7b538c6737a4c6d0090350af2e1776bef.1628779805.git.andreyknvl@gmail.com
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Woody Lin [Thu, 2 Sep 2021 21:57:29 +0000 (14:57 -0700)]
mm/kasan: move kasan.fault to mm/kasan/report.c
Move the boot parameter 'kasan.fault' from hw_tags.c to report.c, so it
can support all KASAN modes - generic, and both tag-based.
Link: https://lkml.kernel.org/r/20210713010536.3161822-1-woodylin@google.com
Signed-off-by: Woody Lin <woodylin@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chen Wandun [Thu, 2 Sep 2021 21:57:26 +0000 (14:57 -0700)]
mm/vmalloc: fix wrong behavior in vread
commit
f608788cd2d6 ("mm/vmalloc: use rb_tree instead of list for vread()
lookups") use rb_tree instread of list to speed up lookup, but function
__find_vmap_area is try to find a vmap_area that include target address,
if target address is smaller than the leftmost node in vmap_area_root, it
will return NULL, then vread will read nothing. This behavior is
different from the primitive semantics.
The correct way is find the first vmap_are that bigger than target addr,
that is what function find_vmap_area_exceed_addr does.
Link: https://lkml.kernel.org/r/20210714015959.3204871-1-chenwandun@huawei.com
Fixes:
f608788cd2d6 ("mm/vmalloc: use rb_tree instead of list for vread() lookups")
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Cc: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Uladzislau Rezki (Sony) [Thu, 2 Sep 2021 21:57:23 +0000 (14:57 -0700)]
lib/test_vmalloc.c: add a new 'nr_pages' parameter
In order to simulate different fixed sizes for vmalloc allocation
introduce a new parameter that sets number of pages to be allocated for
the "fix_size_alloc_test" test.
By default 1 page is used unless a different number is specified over the
new parameter.
Link: https://lkml.kernel.org/r/20210710194151.21370-1-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Uladzislau Rezki (Sony) [Thu, 2 Sep 2021 21:57:19 +0000 (14:57 -0700)]
mm/vmalloc: remove gfpflags_allow_blocking() check
Get rid of gfpflags_allow_blocking() check from the vmalloc() path as it
is supposed to be sleepable anyway. Thus remove it from the
alloc_vmap_area() as well as from the vm_area_alloc_pages().
Link: https://lkml.kernel.org/r/20210707182639.31282-2-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Uladzislau Rezki (Sony) [Thu, 2 Sep 2021 21:57:16 +0000 (14:57 -0700)]
mm/vmalloc: use batched page requests in bulk-allocator
In case of simultaneous vmalloc allocations, for example it is 1GB and 12
CPUs my system is able to hit "BUG: soft lockup" for !CONFIG_PREEMPT
kernel.
RIP: 0010:__alloc_pages_bulk+0xa9f/0xbb0
Call Trace:
__vmalloc_node_range+0x11c/0x2d0
__vmalloc_node+0x4b/0x70
fix_size_alloc_test+0x44/0x60 [test_vmalloc]
test_func+0xe7/0x1f0 [test_vmalloc]
kthread+0x11a/0x140
ret_from_fork+0x22/0x30
To address this issue invoke a bulk-allocator many times until all pages
are obtained, i.e. do batched page requests adding cond_resched()
meanwhile to reschedule. Batched value is hard-coded and is 100 pages per
call.
Link: https://lkml.kernel.org/r/20210707182639.31282-1-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miles Chen [Thu, 2 Sep 2021 21:57:13 +0000 (14:57 -0700)]
mm/sparse: clarify pgdat_to_phys
Clarify pgdat_to_phys() by testing if
pgdat == &contig_page_data when CONFIG_NUMA=n.
We only expect contig_page_data in such case, so we
use &contig_page_data directly instead of pgdat.
No functional change intended when CONFIG_BUG_VM=n.
Comment from Mark [1]:
"
... and I reckon it'd be clearer and more robust to define
pgdat_to_phys() in the same ifdefs as contig_page_data so
that these, stay in-sync. e.g. have:
| #ifdef CONFIG_NUMA
| #define pgdat_to_phys(x) virt_to_phys(x)
| #else /* CONFIG_NUMA */
|
| extern struct pglist_data contig_page_data;
| ...
| #define pgdat_to_phys(x) __pa_symbol(&contig_page_data)
|
| #endif /* CONIFIG_NUMA */
"
[1] https://lore.kernel.org/linux-arm-kernel/
20210615131902.GB47121@C02TD0UTHF1T.local/
Link: https://lkml.kernel.org/r/20210723123342.26406-1-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox [Thu, 2 Sep 2021 21:57:10 +0000 (14:57 -0700)]
include/linux/mmzone.h: avoid a warning in sparse memory support
cppcheck warns that we're possibly losing information by shifting an int.
It's a false positive, because we don't allow for a NUMA node ID that
large, but if we ever change SECTION_NID_SHIFT, it could become a problem,
and in any case this is usually a legitimate warning. Fix it by adding
the necessary cast, which makes the compiler generate the right code.
Link: https://lkml.kernel.org/r/YOya+aBZFFmC476e@casper.infradead.org
Link: https://lkml.kernel.org/r/202107130348.6LsVT9Nc-lkp@intel.com
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Naoya Horiguchi [Thu, 2 Sep 2021 21:57:07 +0000 (14:57 -0700)]
mm/sparse: set SECTION_NID_SHIFT to 6
Currently SECTION_NID_SHIFT is set to 3, which is incorrect because bit 3
and 4 can be overlapped by sub-field for early NID, and can be
unexpectedly set on NUMA systems. There are a few non-critical issues
related to this:
- Having SECTION_TAINT_ZONE_DEVICE set for wrong sections forces
pfn_to_online_page() through the slow path, but doesn't actually break
the kernel.
- A kdump generation tool like makedumpfile uses this field to calculate
the physical address to read. So wrong bits can make the tool access to
wrong address and fail to create kdump. This can be avoided by the
tool, so it's not critical.
To fix it, set SECTION_NID_SHIFT to 6 which is the minimum number of
available bits of section flag field.
Link: https://lkml.kernel.org/r/20210707045548.810271-1-naoya.horiguchi@linux.dev
Fixes:
1f90a3477df3 ("mm: teach pfn_to_online_page() about ZONE_DEVICE section collisions")
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: Kazuhito Hagio <k-hagio-ab@nec.com>
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Wang Wensheng <wangwensheng4@huawei.com>
Cc: Rui Xiang <rui.xiang@huawei.com>
Cc: Kazu <k-hagio-ab@nec.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ohhoon Kwon [Thu, 2 Sep 2021 21:57:04 +0000 (14:57 -0700)]
mm: sparse: remove __section_nr() function
As the last users of __section_nr() are gone, let's remove unused function
__section_nr().
Link: https://lkml.kernel.org/r/20210707150212.855-4-ohoono.kwon@samsung.com
Signed-off-by: Ohhoon Kwon <ohoono.kwon@samsung.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ohhoon Kwon [Thu, 2 Sep 2021 21:57:01 +0000 (14:57 -0700)]
mm: sparse: pass section_nr to find_memory_block
With CONFIG_SPARSEMEM_EXTREME enabled, __section_nr() which converts
mem_section to section_nr could be costly since it iterates all section
roots to check if the given mem_section is in its range.
On the other hand, __nr_to_section() which converts section_nr to
mem_section can be done in O(1).
Let's pass section_nr instead of mem_section ptr to find_memory_block() in
order to reduce needless iterations.
Link: https://lkml.kernel.org/r/20210707150212.855-3-ohoono.kwon@samsung.com
Signed-off-by: Ohhoon Kwon <ohoono.kwon@samsung.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ohhoon Kwon [Thu, 2 Sep 2021 21:56:58 +0000 (14:56 -0700)]
mm: sparse: pass section_nr to section_mark_present
Patch series "mm: sparse: remove __section_nr() function", v4.
This patch (of 3):
With CONFIG_SPARSEMEM_EXTREME enabled, __section_nr() which converts
mem_section to section_nr could be costly since it iterates all section
roots to check if the given mem_section is in its range.
Since both callers of section_mark_present already know section_nr, let's
also pass section_nr as well as mem_section in order to reduce costly
translation.
Link: https://lkml.kernel.org/r/20210707150212.855-1-ohoono.kwon@samsung.com
Link: https://lkml.kernel.org/r/20210707150212.855-2-ohoono.kwon@samsung.com
Signed-off-by: Ohhoon Kwon <ohoono.kwon@samsung.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Muchun Song [Thu, 2 Sep 2021 21:56:55 +0000 (14:56 -0700)]
mm/bootmem_info.c: mark __init on register_page_bootmem_info_section
register_page_bootmem_info_section() is only called from __init functions,
so mark it __init as well.
Link: https://lkml.kernel.org/r/20210817042221.77172-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chen Wandun [Thu, 2 Sep 2021 21:56:52 +0000 (14:56 -0700)]
mm/mremap: fix memory account on do_munmap() failure
mremap will account the delta between new_len and old_len in
vma_to_resize, and then call move_vma when expanding an existing memory
mapping. In function move_vma, there are two scenarios when calling
do_munmap:
1. move_page_tables from old_addr to new_addr success
2. move_page_tables from old_addr to new_addr fail
In first scenario, it should account old_len if do_munmap fail, because
the delta has already been accounted.
In second scenario, new_addr/new_len will assign to old_addr/old_len if
move_page_table fail, so do_munmap is try to unmap new_addr actually, if
do_munmap fail, it should account the new_len, because error code will be
return from move_vma, and delta will be unaccounted. What'more, because
of new_len == old_len, so account old_len also is OK.
In summary, account old_len will be correct if do_munmap fail.
Link: https://lkml.kernel.org/r/20210717101942.120607-1-chenwandun@huawei.com
Fixes:
51df7bcb6151 ("mm/mremap: account memory on do_munmap() failure")
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Acked-by: Dmitry Safonov <dima@arista.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Liam R. Howlett [Thu, 2 Sep 2021 21:56:49 +0000 (14:56 -0700)]
remap_file_pages: Use vma_lookup() instead of find_vma()
Using vma_lookup() verifies the start address is contained in the found vma.
This results in easier to read code.
Link: https://lkml.kernel.org/r/20210817135234.1550204-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@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>
Luigi Rizzo [Thu, 2 Sep 2021 21:56:46 +0000 (14:56 -0700)]
mm/pagemap: add mmap_assert_locked() annotations to find_vma*()
find_vma() and variants need protection when used. This patch adds
mmap_assert_lock() calls in the functions.
To make sure the invariant is satisfied, we also need to add a
mmap_read_lock() around the get_user_pages_remote() call in
get_arg_page(). The lock is not strictly necessary because the mm has
been newly created, but the extra cost is limited because the same mutex
was also acquired shortly before in __bprm_mm_init(), so it is hot and
uncontended.
[penguin-kernel@i-love.sakura.ne.jp: TOMOYO needs the same protection which get_arg_page() needs]
Link: https://lkml.kernel.org/r/58bb6bf7-a57e-8a40-e74b-39584b415152@i-love.sakura.ne.jp
Link: https://lkml.kernel.org/r/20210731175341.3458608-1-lrizzo@google.com
Signed-off-by: Luigi Rizzo <lrizzo@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>
Greg Kroah-Hartman [Thu, 2 Sep 2021 21:56:43 +0000 (14:56 -0700)]
mm: change fault_in_pages_* to have an unsigned size parameter
fault_in_pages_writeable() and fault_in_pages_readable() treat the size
parameter as unsigned, doing pointer math with the value, so make this
explicit and set it to be a size_t type which all callers currently treat
it as anyway.
This solves the issue where static checkers get nervous seeing pointer
arithmetic happening with a signed value.
Link: https://lkml.kernel.org/r/20210727111136.457638-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Jordy Zomer <jordy@pwning.systems>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Huang Ying [Thu, 2 Sep 2021 21:56:40 +0000 (14:56 -0700)]
mm,do_huge_pmd_numa_page: remove unnecessary TLB flushing code
Before commit
c5b5a3dd2c1f ("mm: thp: refactor NUMA fault handling"), the
TLB flushing is done in do_huge_pmd_numa_page() itself via
flush_tlb_range().
But after commit
c5b5a3dd2c1f ("mm: thp: refactor NUMA fault handling"),
the TLB flushing is done in migrate_pages() as in the following code path
anyway.
do_huge_pmd_numa_page
migrate_misplaced_page
migrate_pages
So now, the TLB flushing code in do_huge_pmd_numa_page() becomes
unnecessary. So the code is deleted in this patch to simplify the code.
This is only code cleanup, there's no visible performance difference.
The mmu_notifier_invalidate_range() in do_huge_pmd_numa_page() is
deleted too. Because migrate_pages() takes care of that too when CPU
TLB is flushed.
Link: https://lkml.kernel.org/r/20210720065529.716031-1-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Hellwig [Thu, 2 Sep 2021 21:56:36 +0000 (14:56 -0700)]
mm: remove flush_kernel_dcache_page
flush_kernel_dcache_page is a rather confusing interface that implements a
subset of flush_dcache_page by not being able to properly handle page
cache mapped pages.
The only callers left are in the exec code as all other previous callers
were incorrect as they could have dealt with page cache pages. Replace
the calls to flush_kernel_dcache_page with calls to flush_dcache_page,
which for all architectures does either exactly the same thing, can
contains one or more of the following:
1) an optimization to defer the cache flush for page cache pages not
mapped into userspace
2) additional flushing for mapped page cache pages if cache aliases
are possible
Link: https://lkml.kernel.org/r/20210712060928.4161649-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Hellwig [Thu, 2 Sep 2021 21:56:33 +0000 (14:56 -0700)]
scatterlist: replace flush_kernel_dcache_page with flush_dcache_page
Pages used in scatterlist can be mapped page cache pages (and often are),
so we must use flush_dcache_page here instead of the more limited
flush_kernel_dcache_page that is intended for highmem pages only.
Also remove the PageSlab check given that page_mapping_file as used by the
flush_dcache_page implementations already contains that check.
Link: https://lkml.kernel.org/r/20210712060928.4161649-5-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alex Shi <alexs@kernel.org>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Hellwig [Thu, 2 Sep 2021 21:56:30 +0000 (14:56 -0700)]
mmc: mmc_spi: replace flush_kernel_dcache_page with flush_dcache_page
Pages passed to block drivers can be mapped page cache pages, so we must
use flush_dcache_page here instead of the more limited
flush_kernel_dcache_page that is intended for highmem pages only.
Link: https://lkml.kernel.org/r/20210712060928.4161649-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alex Shi <alexs@kernel.org>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Christoph Hellwig [Thu, 2 Sep 2021 21:56:26 +0000 (14:56 -0700)]
mmc: JZ4740: remove the flush_kernel_dcache_page call in jz4740_mmc_read_data
Patch series "_kernel_dcache_page fixes and removal".
While looking to convert the block layer away from kmap_atomic towards
kmap_local_page and prefeably the helpers that abstract it away I noticed
that a few block drivers directly or implicitly call
flush_kernel_dcache_page before kunmapping a page that has been written
to.
flush_kernel_dcache_page is documented to to be used in such cases, but
flush_dcache_page is actually required when the page could be in the page
cache and mapped to userspace, which is pretty much always the case when
kmapping an arbitrary page. Unfortunately the documentation doesn't
exactly make that clear, which lead to this misused. And it turns out
that only the copy_strings / copy_string_kernel in the exec code were
actually correct users of flush_kernel_dcache_page, which is why I think
we should just remove it and eat the very minor overhead in exec rather
than confusing poor driver writers.
This patch (of 6):
MIPS now implements flush_kernel_dcache_page (as an alias to
flush_dcache_page).
Link: https://lkml.kernel.org/r/20210712060928.4161649-1-hch@lst.de
Link: https://lkml.kernel.org/r/20210712060928.4161649-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Guo Ren <guoren@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Cc: Rich Felker <dalias@libc.org>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Alex Shi <alexs@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Colin Ian King [Thu, 2 Sep 2021 21:56:11 +0000 (14:56 -0700)]
selftests: Fix spelling mistake "cann't" -> "cannot"
There is a spelling mistake in an error message. Fix it.
Link: https://lkml.kernel.org/r/20210826121217.12885-1-colin.king@canonical.com
Signed-off-by: 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>
Po-Hsu Lin [Thu, 2 Sep 2021 21:56:08 +0000 (14:56 -0700)]
selftests/vm: use kselftest skip code for skipped tests
There are several test cases in the vm directory are still using exit 0
when they need to be skipped. Use the kselftest framework to skip code
instead so it can help us to distinguish the return status.
Criterion to filter out what should be fixed in vm directory:
grep -r "exit 0" -B1 | grep -i skip
This change might cause some false-positives if people are running these
test scripts directly and only checking their return codes, which will
change from 0 to 4. However I think the impact should be small as most of
our scripts here are already using this skip code. And there will be no
such issue if running them with the kselftest framework.
Link: https://lkml.kernel.org/r/20210823073433.37653-1-po-hsu.lin@canonical.com
Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shakeel Butt [Thu, 2 Sep 2021 21:56:05 +0000 (14:56 -0700)]
memcg: make memcg->event_list_lock irqsafe
The memcg->event_list_lock is usually taken in the normal context but when
the userspace closes the corresponding eventfd, eventfd_release through
memcg_event_wake takes memcg->event_list_lock with interrupts disabled.
This is not an issue on its own but it creates a nested dependency from
eventfd_ctx->wqh.lock to memcg->event_list_lock.
Independently, for unrelated eventfd, eventfd_signal() can be called in
the irq context, thus making eventfd_ctx->wqh.lock an irq lock. For
example, FPGA DFL driver, VHOST VPDA driver and couple of VFIO drivers.
This will force memcg->event_list_lock to be an irqsafe lock as well.
One way to break the nested dependency between eventfd_ctx->wqh.lock and
memcg->event_list_lock is to add an indirection. However the simplest
solution would be to make memcg->event_list_lock irqsafe. This is cgroup
v1 feature, is in maintenance and may get deprecated in near future. So,
no need to add more code.
BTW this has been discussed previously [1] but there weren't irq users of
eventfd_signal() at the time.
[1] https://www.spinics.net/lists/cgroups/msg06248.html
Link: https://lkml.kernel.org/r/20210830172953.207257-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Thu, 2 Sep 2021 21:56:02 +0000 (14:56 -0700)]
memcg: fix up drain_local_stock comment
Thomas and Vlastimil have noticed that the comment in drain_local_stock
doesn't quite make sense. It talks about a synchronization with the
memory hotplug but there is no actual memory hotplug involvement here. I
meant to talk about cpu hotplug here. Fix that up and hopefuly make the
comment more helpful by referencing the cpu hotplug callback as well.
Link: https://lkml.kernel.org/r/YRDwOhVglJmY7ES5@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miaohe Lin [Thu, 2 Sep 2021 21:55:59 +0000 (14:55 -0700)]
mm, memcg: save some atomic ops when flush is already true
Add 'else' to save some atomic ops in obj_stock_flush_required() when
flush is already true. No functional change intended here.
Link: https://lkml.kernel.org/r/20210807082835.61281-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Alex Shi <alexs@kernel.org>
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>
Miaohe Lin [Thu, 2 Sep 2021 21:55:56 +0000 (14:55 -0700)]
mm, memcg: remove unused functions
Since commit
2d146aa3aa84 ("mm: memcontrol: switch to rstat"), last user
of memcg_stat_item_in_bytes() is gone. And since commit
fa40d1ee9f15
("mm: vmscan: memcontrol: remove mem_cgroup_select_victim_node()"), only
the declaration of mem_cgroup_select_victim_node() is remained here.
Remove them.
Link: https://lkml.kernel.org/r/20210807082835.61281-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
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>
Baolin Wang [Thu, 2 Sep 2021 21:55:53 +0000 (14:55 -0700)]
mm: memcontrol: set the correct memcg swappiness restriction
Since commit
c843966c556d ("mm: allow swappiness that prefers reclaiming
anon over the file workingset") has expended the swappiness value to make
swap to be preferred in some systems. We should also change the memcg
swappiness restriction to allow memcg swap-preferred.
Link: https://lkml.kernel.org/r/d77469b90c45c49953ccbc51e54a1d465bc18f70.1627626255.git.baolin.wang@linux.alibaba.com
Fixes:
c843966c556d ("mm: allow swappiness that prefers reclaiming anon over the file workingset")
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Thu, 2 Sep 2021 21:55:49 +0000 (14:55 -0700)]
memcg: replace in_interrupt() by !in_task() in active_memcg()
set_active_memcg() uses in_interrupt() check to select proper storage for
cgroup: pointer on task struct or per-cpu pointer.
It isn't fully correct: obsoleted in_interrupt() includes tasks with
disabled BH. It's better to use '!in_task()' instead.
Link: https://lkml.org/lkml/2021/7/26/487
Link: https://lkml.kernel.org/r/ed4448b0-4970-616f-7368-ef9dd3cb628d@virtuozzo.com
Fixes:
37d5985c003d ("mm: kmem: prepare remote memcg charging infra for interrupt contexts")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shakeel Butt [Thu, 2 Sep 2021 21:55:46 +0000 (14:55 -0700)]
memcg: cleanup racy sum avoidance code
We used to have per-cpu memcg and lruvec stats and the readers have to
traverse and sum the stats from each cpu. This summing was racy and may
expose transient negative values. So, an explicit check was added to
avoid such scenarios. Now these stats are moved to rstat infrastructure
and are no more per-cpu, so we can remove the fixup for transient negative
values.
Link: https://lkml.kernel.org/r/20210728012243.3369123-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Thu, 2 Sep 2021 21:55:43 +0000 (14:55 -0700)]
memcg: enable accounting for ldt_struct objects
Each task can request own LDT and force the kernel to allocate up to 64Kb
memory per-mm.
There are legitimate workloads with hundreds of processes and there can be
hundreds of workloads running on large machines. The unaccounted memory
can cause isolation issues between the workloads particularly on highly
utilized machines.
It makes sense to account for this objects to restrict the host's memory
consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/38010594-50fe-c06d-7cb0-d1f77ca422f3@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yutian Yang <nglaive@gmail.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Thu, 2 Sep 2021 21:55:39 +0000 (14:55 -0700)]
memcg: enable accounting for posix_timers_cache slab
A program may create multiple interval timers using timer_create(). For
each timer the kernel preallocates a "queued real-time signal",
Consequently, the number of timers is limited by the RLIMIT_SIGPENDING
resource limit. The allocated object is quite small, ~250 bytes, but even
the default signal limits allow to consume up to 100 megabytes per user.
It makes sense to account for them to limit the host's memory consumption
from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/57795560-025c-267c-6b1a-dea852d95530@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yutian Yang <nglaive@gmail.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Thu, 2 Sep 2021 21:55:35 +0000 (14:55 -0700)]
memcg: enable accounting for signals
When a user send a signal to any another processes it forces the kernel to
allocate memory for 'struct sigqueue' objects. The number of signals is
limited by RLIMIT_SIGPENDING resource limit, but even the default settings
allow each user to consume up to several megabytes of memory.
It makes sense to account for these allocations to restrict the host's
memory consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/e34e958c-e785-712e-a62a-2c7b66c646c7@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yutian Yang <nglaive@gmail.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Thu, 2 Sep 2021 21:55:31 +0000 (14:55 -0700)]
memcg: enable accounting of ipc resources
When user creates IPC objects it forces kernel to allocate memory for
these long-living objects.
It makes sense to account them to restrict the host's memory consumption
from inside the memcg-limited container.
This patch enables accounting for IPC shared memory segments, messages
semaphores and semaphore's undo lists.
Link: https://lkml.kernel.org/r/d6507b06-4df6-78f8-6c54-3ae86e3b5339@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yutian Yang <nglaive@gmail.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Thu, 2 Sep 2021 21:55:27 +0000 (14:55 -0700)]
memcg: enable accounting for new namesapces and struct nsproxy
Container admin can create new namespaces and force kernel to allocate up
to several pages of memory for the namespaces and its associated
structures.
Net and uts namespaces have enabled accounting for such allocations. It
makes sense to account for rest ones to restrict the host's memory
consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/5525bcbf-533e-da27-79b7-158686c64e13@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yutian Yang <nglaive@gmail.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Thu, 2 Sep 2021 21:55:23 +0000 (14:55 -0700)]
memcg: enable accounting for fasync_cache
fasync_struct is used by almost all character device drivers to set up the
fasync queue, and for regular files by the file lease code. This
structure is quite small but long-living and it can be assigned for any
open file.
It makes sense to account for its allocations to restrict the host's
memory consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/1b408625-d71c-0b26-b0b6-9baf00f93e69@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yutian Yang <nglaive@gmail.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Thu, 2 Sep 2021 21:55:19 +0000 (14:55 -0700)]
memcg: enable accounting for file lock caches
User can create file locks for each open file and force kernel to allocate
small but long-living objects per each open file.
It makes sense to account for these objects to limit the host's memory
consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/b009f4c7-f0ab-c0ec-8e83-918f47d677da@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yutian Yang <nglaive@gmail.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Thu, 2 Sep 2021 21:55:14 +0000 (14:55 -0700)]
memcg: enable accounting for pollfd and select bits arrays
User can call select/poll system calls with a large number of assigned
file descriptors and force kernel to allocate up to several pages of
memory till end of these sleeping system calls. We have here long-living
unaccounted per-task allocations.
It makes sense to account for these allocations to restrict the host's
memory consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/56e31cb5-6e1e-bdba-d7ca-be64b9842363@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yutian Yang <nglaive@gmail.com>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Thu, 2 Sep 2021 21:55:10 +0000 (14:55 -0700)]
memcg: enable accounting for mnt_cache entries
Patch series "memcg accounting from OpenVZ", v7.
OpenVZ uses memory accounting 20+ years since v2.2.x linux kernels.
Initially we used our own accounting subsystem, then partially committed
it to upstream, and a few years ago switched to cgroups v1. Now we're
rebasing again, revising our old patches and trying to push them upstream.
We try to protect the host system from any misuse of kernel memory
allocation triggered by untrusted users inside the containers.
Patch-set is addressed mostly to cgroups maintainers and cgroups@ mailing
list, though I would be very grateful for any comments from maintainersi
of affected subsystems or other people added in cc:
Compared to the upstream, we additionally account the following kernel objects:
- network devices and its Tx/Rx queues
- ipv4/v6 addresses and routing-related objects
- inet_bind_bucket cache objects
- VLAN group arrays
- ipv6/sit: ip_tunnel_prl
- scm_fp_list objects used by SCM_RIGHTS messages of Unix sockets
- nsproxy and namespace objects itself
- IPC objects: semaphores, message queues and share memory segments
- mounts
- pollfd and select bits arrays
- signals and posix timers
- file lock
- fasync_struct used by the file lease code and driver's fasync queues
- tty objects
- per-mm LDT
We have an incorrect/incomplete/obsoleted accounting for few other kernel
objects: sk_filter, af_packets, netlink and xt_counters for iptables.
They require rework and probably will be dropped at all.
Also we're going to add an accounting for nft, however it is not ready
yet.
We have not tested performance on upstream, however, our performance team
compares our current RHEL7-based production kernel and reports that they
are at least not worse as the according original RHEL7 kernel.
This patch (of 10):
The kernel allocates ~400 bytes of 'struct mount' for any new mount.
Creating a new mount namespace clones most of the parent mounts, and this
can be repeated many times. Additionally, each mount allocates up to
PATH_MAX=4096 bytes for mnt->mnt_devname.
It makes sense to account for these allocations to restrict the host's
memory consumption from inside the memcg-limited container.
Link: https://lkml.kernel.org/r/045db11f-4a45-7c9b-2664-5b32c2b44943@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Yutian Yang <nglaive@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yutian Yang [Thu, 2 Sep 2021 21:55:07 +0000 (14:55 -0700)]
memcg: charge fs_context and legacy_fs_context
This patch adds accounting flags to fs_context and legacy_fs_context
allocation sites so that kernel could correctly charge these objects.
We have written a PoC to demonstrate the effect of the missing-charging
bugs. The PoC takes around 1,200MB unaccounted memory, while it is
charged for only 362MB memory usage. We evaluate the PoC on QEMU x86_64
v5.2.90 + Linux kernel v5.10.19 + Debian buster. All the limitations
including ulimits and sysctl variables are set as default. Specifically,
the hard NOFILE limit and nr_open in sysctl are both 1,048,576.
/*------------------------- POC code ----------------------------*/
#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/file.h>
#include <time.h>
#include <sys/wait.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <sched.h>
#include <fcntl.h>
#include <linux/mount.h>
#define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \
} while (0)
#define STACK_SIZE (8 * 1024)
#ifndef __NR_fsopen
#define __NR_fsopen 430
#endif
static inline int fsopen(const char *fs_name, unsigned int flags)
{
return syscall(__NR_fsopen, fs_name, flags);
}
static char thread_stack[512][STACK_SIZE];
int thread_fn(void* arg)
{
for (int i = 0; i< 800000; ++i) {
int fsfd = fsopen("nfs", FSOPEN_CLOEXEC);
if (fsfd == -1) {
errExit("fsopen");
}
}
while(1);
return 0;
}
int main(int argc, char *argv[]) {
int thread_pid;
for (int i = 0; i < 1; ++i) {
thread_pid = clone(thread_fn, thread_stack[i] + STACK_SIZE, \
SIGCHLD, NULL);
}
while(1);
return 0;
}
/*-------------------------- end --------------------------------*/
Link: https://lkml.kernel.org/r/1626517201-24086-1-git-send-email-nglaive@gmail.com
Signed-off-by: Yutian Yang <nglaive@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <shenwenbo@zju.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shakeel Butt [Thu, 2 Sep 2021 21:55:04 +0000 (14:55 -0700)]
memcg: infrastructure to flush memcg stats
At the moment memcg stats are read in four contexts:
1. memcg stat user interfaces
2. dirty throttling
3. page fault
4. memory reclaim
Currently the kernel flushes the stats for first two cases. Flushing the
stats for remaining two casese may have performance impact. Always
flushing the memcg stats on the page fault code path may negatively
impacts the performance of the applications. In addition flushing in the
memory reclaim code path, though treated as slowpath, can become the
source of contention for the global lock taken for stat flushing because
when system or memcg is under memory pressure, many tasks may enter the
reclaim path.
This patch uses following mechanisms to solve these challenges:
1. Periodically flush the stats from root memcg every 2 seconds. This
will time limit the out of sync stats.
2. Asynchronously flush the stats after fixed number of stat updates.
In the worst case the stat can be out of sync by O(nr_cpus * BATCH) for
2 seconds.
3. For avoiding thundering herd to flush the stats particularly from
the memory reclaim context, introduce memcg local spinlock and let only
one flusher active at a time. This could have been done through
cgroup_rstat_lock lock but that lock is used by other subsystem and for
userspace reading memcg stats. So, it is better to keep flushers
introduced by this patch decoupled from cgroup_rstat_lock. However we
would have to use irqsafe version of rstat flush but that is fine as
this code path will be flushing for whole tree and do the work for
everyone. No one will be waiting for that worker.
[shakeelb@google.com: fix sleep-in-wrong context bug]
Link: https://lkml.kernel.org/r/20210716212137.1391164-2-shakeelb@google.com
Link: https://lkml.kernel.org/r/20210714013948.270662-2-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shakeel Butt [Thu, 2 Sep 2021 21:55:00 +0000 (14:55 -0700)]
memcg: switch lruvec stats to rstat
The commit
2d146aa3aa84 ("mm: memcontrol: switch to rstat") switched memcg
stats to rstat infrastructure but skipped the conversion of the lruvec
stats as such stats are read in the performance critical code paths and
flushing stats may have impacted the performances of the applications.
This patch converts the lruvec stats to rstat and later patches add
mechanisms to keep the performance impact to minimum.
The rstat conversion comes with the price i.e. memory cost. Effectively
this patch reverts the savings done by the commit
f3344adf38bd ("mm:
memcontrol: optimize per-lruvec stats counter memory usage"). However
this cost is justified due to negative impact of the inaccurate lruvec
stats on many heuristics. One such case is reported in [1].
The memory reclaim code is filled with plethora of heuristics and many of
those heuristics reads the lruvec stats. So, inaccurate stats can make
such heuristics ineffective. [1] reports the impact of inaccurate lruvec
stats on the "cache trim mode" heuristic. Inaccurate lruvec stats can
impact the deactivation and aging anon heuristics as well.
[1] https://lore.kernel.org/linux-mm/
20210311004449.1170308-1-ying.huang@intel.com/
Link: https://lkml.kernel.org/r/20210716212137.1391164-1-shakeelb@google.com
Link: https://lkml.kernel.org/r/20210714013948.270662-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vasily Averin [Thu, 2 Sep 2021 21:54:57 +0000 (14:54 -0700)]
memcg: enable accounting for pids in nested pid namespaces
Commit
5d097056c9a0 ("kmemcg: account certain kmem allocations to memcg")
enabled memcg accounting for pids allocated from init_pid_ns.pid_cachep,
but forgot to adjust the setting for nested pid namespaces. As a result,
pid memory is not accounted exactly where it is really needed, inside
memcg-limited containers with their own pid namespaces.
Pid was one the first kernel objects enabled for memcg accounting.
init_pid_ns.pid_cachep marked by SLAB_ACCOUNT and we can expect that any
new pids in the system are memcg-accounted.
Though recently I've noticed that it is wrong. nested pid namespaces
creates own slab caches for pid objects, nested pids have increased size
because contain id both for all parent and for own pid namespaces. The
problem is that these slab caches are _NOT_ marked by SLAB_ACCOUNT, as a
result any pids allocated in nested pid namespaces are not
memcg-accounted.
Pid struct in nested pid namespace consumes up to 500 bytes memory, 100000
such objects gives us up to ~50Mb unaccounted memory, this allow container
to exceed assigned memcg limits.
Link: https://lkml.kernel.org/r/8b6de616-fd1a-02c6-cbdb-976ecdcfa604@virtuozzo.com
Fixes:
5d097056c9a0 ("kmemcg: account certain kmem allocations to memcg")
Cc: stable@vger.kernel.org
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Suren Baghdasaryan [Thu, 2 Sep 2021 21:54:54 +0000 (14:54 -0700)]
mm, memcg: inline swap-related functions to improve disabled memcg config
Inline mem_cgroup_try_charge_swap, mem_cgroup_uncharge_swap and
cgroup_throttle_swaprate functions to perform mem_cgroup_disabled static
key check inline before calling the main body of the function. This
minimizes the memcg overhead in the pagefault and exit_mmap paths when
memcgs are disabled using cgroup_disable=memory command-line option. This
change results in ~1% overhead reduction when running PFT test [1]
comparing {CONFIG_MEMCG=n} against {CONFIG_MEMCG=y, cgroup_disable=memory}
configuration on an 8-core ARM64 Android device.
[1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite
Link: https://lkml.kernel.org/r/20210713010934.299876-3-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Suren Baghdasaryan [Thu, 2 Sep 2021 21:54:50 +0000 (14:54 -0700)]
mm, memcg: inline mem_cgroup_{charge/uncharge} to improve disabled memcg config
Inline mem_cgroup_{charge/uncharge} and mem_cgroup_uncharge_list functions
functions to perform mem_cgroup_disabled static key check inline before
calling the main body of the function. This minimizes the memcg overhead
in the pagefault and exit_mmap paths when memcgs are disabled using
cgroup_disable=memory command-line option.
This change results in ~0.4% overhead reduction when running PFT test [1]
comparing {CONFIG_MEMCG=n} against {CONFIG_MEMCG=y, cgroup_disable=memory}
configuration on an 8-core ARM64 Android device.
[1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite
Link: https://lkml.kernel.org/r/20210713010934.299876-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alex Shi <alexs@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Suren Baghdasaryan [Thu, 2 Sep 2021 21:54:47 +0000 (14:54 -0700)]
mm, memcg: add mem_cgroup_disabled checks in vmpressure and swap-related functions
Add mem_cgroup_disabled check in vmpressure, mem_cgroup_uncharge_swap and
cgroup_throttle_swaprate functions. This minimizes the memcg overhead in
the pagefault and exit_mmap paths when memcgs are disabled using
cgroup_disable=memory command-line option.
This change results in ~2.1% overhead reduction when running PFT test [1]
comparing {CONFIG_MEMCG=n, CONFIG_MEMCG_SWAP=n} against {CONFIG_MEMCG=y,
CONFIG_MEMCG_SWAP=y, cgroup_disable=memory} configuration on an 8-core
ARM64 Android device.
[1] https://lkml.org/lkml/2006/8/29/294 also used in mmtests suite
Link: https://lkml.kernel.org/r/20210713010934.299876-1-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 2 Sep 2021 21:54:43 +0000 (14:54 -0700)]
shmem: shmem_writepage() split unlikely i915 THP
drivers/gpu/drm/i915/gem/i915_gem_shmem.c contains a shmem_writeback()
which calls shmem_writepage() from a shrinker: that usually works well
enough; but if /sys/kernel/mm/transparent_hugepage/shmem_enabled has been
set to "always" (intended to be usable) or "force" (forces huge everywhere
for easy testing), shmem_writepage() is surprised to be called with a huge
page, and crashes on the VM_BUG_ON_PAGE(PageCompound) (I did not find out
where the crash happens when CONFIG_DEBUG_VM is off).
LRU page reclaim always splits the shmem huge page first: I'd prefer not
to demand that of i915, so check and split compound in shmem_writepage().
Patch history: when first sent last year
http://lkml.kernel.org/r/alpine.LSU.2.11.
2008301401390.5954@eggly.anvils
https://lore.kernel.org/linux-mm/
20200919042009.bomzxmrg7%25akpm@linux-foundation.org/
Matthew Wilcox noticed that tail pages were wrongly left clean. This
version brackets the split with Set and Clear PageDirty as he suggested:
which works very well, even if it falls short of our aspirations. And
recently I realized that the crash is not limited to the testing option
"force", but affects "always" too: which is more important to fix.
Link: https://lkml.kernel.org/r/bac6158c-8b3d-4dca-cffc-4982f58d9794@google.com
Fixes:
2d6692e642e7 ("drm/i915: Start writeback from the shrinker")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 2 Sep 2021 21:54:40 +0000 (14:54 -0700)]
huge tmpfs: decide stat.st_blksize by shmem_is_huge()
4.18 commit
89fdcd262fd4 ("mm: shmem: make stat.st_blksize return huge
page size if THP is on") added is_huge_enabled() to decide st_blksize: if
hugeness is to be defined per file, that will need to be replaced by
shmem_is_huge().
This does give a different answer (No) for small files on a
"huge=within_size" mount: but that can be considered a minor bugfix. And
a different answer (No) for default files on a "huge=advise" mount: I'm
reluctant to complicate it, just to reproduce the same debatable answer as
before.
Link: https://lkml.kernel.org/r/af7fb3f9-4415-9e8e-fdac-b1a5253ad21@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 2 Sep 2021 21:54:37 +0000 (14:54 -0700)]
huge tmpfs: shmem_is_huge(vma, inode, index)
Extend shmem_huge_enabled(vma) to shmem_is_huge(vma, inode, index), so
that a consistent set of checks can be applied, even when the inode is
accessed through read/write syscalls (with NULL vma) instead of mmaps (the
index argument is seldom of interest, but required by mount option
"huge=within_size"). Clean up and rearrange the checks a little.
This then replaces the checks which shmem_fault() and shmem_getpage_gfp()
were making, and eliminates the SGP_HUGE and SGP_NOHUGE modes.
Replace a couple of 0s by explicit SHMEM_HUGE_NEVERs; and replace the
obscure !shmem_mapping() symlink check by explicit S_ISLNK() - nothing
else needs that symlink check, so leave it there in shmem_getpage_gfp().
Link: https://lkml.kernel.org/r/23a77889-2ddc-b030-75cd-44ca27fd4d1@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 2 Sep 2021 21:54:34 +0000 (14:54 -0700)]
huge tmpfs: SGP_NOALLOC to stop collapse_file() on race
khugepaged's collapse_file() currently uses SGP_NOHUGE to tell
shmem_getpage() not to try allocating a huge page, in the very unlikely
event that a racing hole-punch removes the swapped or fallocated page as
soon as i_pages lock is dropped.
We want to consolidate shmem's huge decisions, removing SGP_HUGE and
SGP_NOHUGE; but cannot quite persuade ourselves that it's okay to regress
the protection in this case - Yang Shi points out that the huge page would
remain indefinitely, charged to root instead of the intended memcg.
collapse_file() should not even allocate a small page in this case: why
proceed if someone is punching a hole? SGP_READ is almost the right flag
here, except that it optimizes away from a fallocated page, with NULL to
tell caller to fill with zeroes (like a hole); whereas collapse_file()'s
sequence relies on using a cache page. Add SGP_NOALLOC just for this.
There are too many consecutive "if (page"s there in shmem_getpage_gfp():
group it better; and fix the outdated "bring it back from swap" comment.
Link: https://lkml.kernel.org/r/1355343b-acf-4653-ef79-6aee40214ac5@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 2 Sep 2021 21:54:31 +0000 (14:54 -0700)]
huge tmpfs: move shmem_huge_enabled() upwards
shmem_huge_enabled() is about to be enhanced into shmem_is_huge(), so that
it can be used more widely throughout: before making functional changes,
shift it to its final position (to avoid forward declaration).
Link: https://lkml.kernel.org/r/16fec7b7-5c84-415a-8586-69d8bf6a6685@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 2 Sep 2021 21:54:27 +0000 (14:54 -0700)]
huge tmpfs: revert shmem's use of transhuge_vma_enabled()
5.14 commit
e6be37b2e7bd ("mm/huge_memory.c: add missing read-only THP
checking in transparent_hugepage_enabled()") added transhuge_vma_enabled()
as a wrapper for two very different checks (one check is whether the app
has marked its address range not to use THPs, the other check is whether
the app is running in a hierarchy that has been marked never to use THPs).
shmem_huge_enabled() prefers to show those two checks explicitly, as
before.
Link: https://lkml.kernel.org/r/45e5338-18d-c6f9-c17e-34f510bc1728@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 2 Sep 2021 21:54:24 +0000 (14:54 -0700)]
huge tmpfs: remove shrinklist addition from shmem_setattr()
There's a block of code in shmem_setattr() to add the inode to
shmem_unused_huge_shrink()'s shrinklist when lowering i_size: it dates
from before 5.7 changed truncation to do split_huge_page() for itself, and
should have been removed at that time.
I am over-stating that: split_huge_page() can fail (notably if there's an
extra reference to the page at that time), so there might be value in
retrying. But there were already retries as truncation worked through the
tails, and this addition risks repeating unsuccessful retries
indefinitely: I'd rather remove it now, and work on reducing the chance of
split_huge_page() failures separately, if we need to.
Link: https://lkml.kernel.org/r/b73b3492-8822-18f9-83e2-938528cdde94@google.com
Fixes:
71725ed10c40 ("mm: huge tmpfs: try to split_huge_page() when punching hole")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 2 Sep 2021 21:54:21 +0000 (14:54 -0700)]
huge tmpfs: fix split_huge_page() after FALLOC_FL_KEEP_SIZE
A successful shmem_fallocate() guarantees that the extent has been
reserved, even beyond i_size when the FALLOC_FL_KEEP_SIZE flag was used.
But that guarantee is broken by shmem_unused_huge_shrink()'s attempts to
split huge pages and free their excess beyond i_size; and by other uses of
split_huge_page() near i_size.
It's sad to add a shmem inode field just for this, but I did not find a
better way to keep the guarantee. A flag to say KEEP_SIZE has been used
would be cheaper, but I'm averse to unclearable flags. The fallocend
field is not perfect either (many disjoint ranges might be fallocated),
but good enough; and gains another use later on.
Link: https://lkml.kernel.org/r/ca9a146-3a59-6cd3-7f28-e9a044bb1052@google.com
Fixes:
779750d20b93 ("shmem: split huge pages beyond i_size under memory pressure")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 2 Sep 2021 21:54:18 +0000 (14:54 -0700)]
huge tmpfs: fix fallocate(vanilla) advance over huge pages
Patch series "huge tmpfs: shmem_is_huge() fixes and cleanups".
A series of huge tmpfs fixes and cleanups.
This patch (of 9):
shmem_fallocate() goes to a lot of trouble to leave its newly allocated
pages !Uptodate, partly to identify and undo them on failure, partly to
leave the overhead of clearing them until later. But the huge page case
did not skip to the end of the extent, walked through the tail pages one
by one, and appeared to work just fine: but in doing so, cleared and
Uptodated the huge page, so there was no way to undo it on failure.
And by setting Uptodate too soon, it messed up both its nr_falloced and
nr_unswapped counts, so that the intended "time to give up" heuristic did
not work at all.
Now advance immediately to the end of the huge extent, with a comment on
why this is more than just an optimization. But although this speeds up
huge tmpfs fallocation, it does leave the clearing until first use, and
some users may have come to appreciate slow fallocate but fast first use:
if they complain, then we can consider adding a pass to clear at the end.
Link: https://lkml.kernel.org/r/da632211-8e3e-6b1-aee-ab24734429a0@google.com
Link: https://lkml.kernel.org/r/16201bd2-70e-37e2-e89b-5f929430da@google.com
Fixes:
800d8c63b2e9 ("shmem: add huge pages support")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@surriel.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>
Miaohe Lin [Thu, 2 Sep 2021 21:54:15 +0000 (14:54 -0700)]
shmem: include header file to declare swap_info
It's bad to extern swap_info[] in .c. Include corresponding header file
instead.
Link: https://lkml.kernel.org/r/20210812120350.49801-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miaohe Lin [Thu, 2 Sep 2021 21:54:12 +0000 (14:54 -0700)]
shmem: remove unneeded function forward declaration
The forward declaration for shmem_should_replace_page() and
shmem_replace_page() is unnecessary. Remove them.
Link: https://lkml.kernel.org/r/20210812120350.49801-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miaohe Lin [Thu, 2 Sep 2021 21:54:09 +0000 (14:54 -0700)]
shmem: remove unneeded header file
mfill_atomic_install_pte() is introduced to install pte and update mmu
cache since commit
bf6ebd97aba0 ("userfaultfd/shmem: modify
shmem_mfill_atomic_pte to use install_pte()"). So we should remove
tlbflush.h as update_mmu_cache() is not called here now.
Link: https://lkml.kernel.org/r/20210812120350.49801-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Miaohe Lin [Thu, 2 Sep 2021 21:54:06 +0000 (14:54 -0700)]
shmem: remove unneeded variable ret
Patch series "Cleanups for shmem".
This series contains cleanups to remove unneeded variable, header file,
function forward declaration and so on. More details can be found in the
respective changelogs.
This patch (of 4):
The local variable ret is always equal to -ENOMEM and never touched. So
remove it and return -ENOMEM directly to simplify the code.
Link: https://lkml.kernel.org/r/20210812120350.49801-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210812120350.49801-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sebastian Andrzej Siewior [Thu, 2 Sep 2021 21:54:03 +0000 (14:54 -0700)]
shmem: use raw_spinlock_t for ->stat_lock
Each CPU has SHMEM_INO_BATCH inodes available in `->ino_batch' which is
per-CPU. Access here is serialized by disabling preemption. If the pool
is empty, it gets reloaded from `->next_ino'. Access here is serialized
by ->stat_lock which is a spinlock_t and can not be acquired with disabled
preemption.
One way around it would make per-CPU ino_batch struct containing the inode
number a local_lock_t.
Another solution is to promote ->stat_lock to a raw_spinlock_t. The
critical sections are short. The mpol_put() must be moved outside of the
critical section to avoid invoking the destructor with disabled
preemption.
Link: https://lkml.kernel.org/r/20210806142916.jdwkb5bx62q5fwfo@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
John Hubbard [Thu, 2 Sep 2021 21:54:00 +0000 (14:54 -0700)]
mm: delete unused get_kernel_page()
get_kernel_page() was added in 2012 by [1]. It was used for a while for
NFS, but then in 2014, a refactoring [2] removed all callers, and it has
apparently not been used since.
Remove get_kernel_page() because it has no callers.
[1] commit
18022c5d8627 ("mm: add get_kernel_page[s] for pinning of
kernel addresses for I/O")
[2] commit
91f79c43d1b5 ("new helper: iov_iter_get_pages_alloc()")
Link: https://lkml.kernel.org/r/20210729221847.1165665-1-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Thu, 2 Sep 2021 21:53:57 +0000 (14:53 -0700)]
fs, mm: fix race in unlinking swapfile
We had a recurring situation in which admin procedures setting up
swapfiles would race with test preparation clearing away swapfiles; and
just occasionally that got stuck on a swapfile "(deleted)" which could
never be swapped off. That is not supposed to be possible.
2.6.28 commit
f9454548e17c ("don't unlink an active swapfile") admitted
that it was leaving a race window open: now close it.
may_delete() makes the IS_SWAPFILE check (amongst many others) before
inode_lock has been taken on target: now repeat just that simple check in
vfs_unlink() and vfs_rename(), after taking inode_lock.
Which goes most of the way to fixing the race, but swapon() must also
check after it acquires inode_lock, that the file just opened has not
already been unlinked.
Link: https://lkml.kernel.org/r/e17b91ad-a578-9a15-5e3-4989e0f999b5@google.com
Fixes:
f9454548e17c ("don't unlink an active swapfile")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
John Hubbard [Thu, 2 Sep 2021 21:53:54 +0000 (14:53 -0700)]
mm/gup: remove try_get_page(), call try_get_compound_head() directly
try_get_page() is very similar to try_get_compound_head(), and in fact
try_get_page() has fallen a little behind in terms of maintenance:
try_get_compound_head() handles speculative page references more
thoroughly.
There are only two try_get_page() callsites, so just call
try_get_compound_head() directly from those, and remove try_get_page()
entirely.
Also, seeing as how this changes try_get_compound_head() into a non-static
function, provide some kerneldoc documentation for it.
Link: https://lkml.kernel.org/r/20210813044133.1536842-4-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
John Hubbard [Thu, 2 Sep 2021 21:53:51 +0000 (14:53 -0700)]
mm/gup: small refactoring: simplify try_grab_page()
try_grab_page() does the same thing as try_grab_compound_head(..., refs=1,
...), just with a different API. So there is a lot of code duplication
there.
Change try_grab_page() to call try_grab_compound_head(), while keeping the
API contract identical for callers.
Also, now that try_grab_compound_head() always has a caller, remove the
__maybe_unused annotation.
Link: https://lkml.kernel.org/r/20210813044133.1536842-3-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
John Hubbard [Thu, 2 Sep 2021 21:53:48 +0000 (14:53 -0700)]
mm/gup: documentation corrections for gup/pup
Patch series "A few gup refactorings and documentation updates", v3.
While reviewing some of the other things going on around gup.c, I noticed
that the documentation was wrong for a few of the routines that I wrote.
And then I noticed that there was some significant code duplication too.
So this fixes those issues.
This is not entirely risk-free, but after looking closely at this, I think
it's actually a useful improvement, getting rid of the code duplication
here.
This patch (of 3):
The documentation for try_grab_compound_head() and try_grab_page() has
fallen a little out of date. Update and clarify a few points.
Also make it kerneldoc-correct, by adding @args documentation.
Link: https://lkml.kernel.org/r/20210813044133.1536842-1-jhubbard@nvidia.com
Link: https://lkml.kernel.org/r/20210813044133.1536842-2-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
projects / platform / kernel / linux-rpi.git / log