Paul E. McKenney [Fri, 4 Sep 2020 18:54:52 +0000 (11:54 -0700)]
Merge branch 'csd.2020.09.04a' into HEAD
csd.2020.09.04a: CPU smp_call_function() torture tests.
Wei Yongjun [Mon, 6 Jul 2020 13:49:41 +0000 (21:49 +0800)]
smp: Make symbol 'csd_bug_count' static
The sparse tool complains as follows:
kernel/smp.c:107:10: warning:
symbol 'csd_bug_count' was not declared. Should it be static?
Because variable is not used outside of smp.c, this commit marks it
static.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Paul E. McKenney [Tue, 30 Jun 2020 20:22:54 +0000 (13:22 -0700)]
kernel/smp: Provide CSD lock timeout diagnostics
This commit causes csd_lock_wait() to emit diagnostics when a CPU
fails to respond quickly enough to one of the smp_call_function()
family of function calls. These diagnostics are enabled by a new
CSD_LOCK_WAIT_DEBUG Kconfig option that depends on DEBUG_KERNEL.
This commit was inspired by an earlier patch by Josef Bacik.
[ paulmck: Fix for syzbot+
0f719294463916a3fc0e@syzkaller.appspotmail.com ]
[ paulmck: Fix KASAN use-after-free issue reported by Qian Cai. ]
[ paulmck: Fix botched nr_cpu_ids comparison per Dan Carpenter. ]
[ paulmck: Apply Peter Zijlstra feedback. ]
Link: https://lore.kernel.org/lkml/00000000000042f21905a991ecea@google.com
Link: https://lore.kernel.org/lkml/0000000000002ef21705a9933cf3@google.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Tue, 30 Jun 2020 00:21:32 +0000 (17:21 -0700)]
smp: Add source and destination CPUs to __call_single_data
This commit adds a destination CPU to __call_single_data, and is inspired
by an earlier commit by Peter Zijlstra. This version adds #ifdef to
permit use by 32-bit systems and supplying the destination CPU for all
smp_call_function*() requests, not just smp_call_function_single().
If need be, 32-bit systems could be accommodated by shrinking the flags
field to 16 bits (the atomic_t variant is currently unused) and by
providing only eight bits for CPU on such systems.
It is not clear that the addition of the fields to __call_single_node
are really needed.
[ paulmck: Apply Boqun Feng feedback on 32-bit builds. ]
Link: https://lore.kernel.org/lkml/20200615164048.GC2531@hirez.programming.kicks-ass.net/
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 3 Sep 2020 16:47:42 +0000 (09:47 -0700)]
Merge branch 'strictgp.2020.08.24a' into HEAD
strictgp.2020.08.24a: Strict grace periods for KASAN testing.
Paul E. McKenney [Thu, 3 Sep 2020 16:47:01 +0000 (09:47 -0700)]
Merge branch 'scftorture.2020.08.24a' into HEAD
scftorture.2020.08.24a: Torture tests for smp_call_function() and friends.
Paul E. McKenney [Thu, 3 Sep 2020 16:42:02 +0000 (09:42 -0700)]
Merge branches 'doc.2020.08.24a', 'fixes.2020.09.03b' and 'torture.2020.08.24a' into HEAD
doc.2020.08.24a: Documentation updates.
fixes.2020.09.03b: Miscellaneous fixes.
torture.2020.08.24a: Torture-test updates.
Zqiang [Fri, 14 Aug 2020 06:45:57 +0000 (14:45 +0800)]
rcu: Shrink each possible cpu krcp
CPUs can go offline shortly after kfree_call_rcu() has been invoked,
which can leave memory stranded until those CPUs come back online.
This commit therefore drains the kcrp of each CPU, not just the
ones that happen to be online.
Acked-by: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Zqiang <qiang.zhang@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Joel Fernandes (Google) [Thu, 18 Jun 2020 20:29:49 +0000 (16:29 -0400)]
rcu/segcblist: Prevent useless GP start if no CBs to accelerate
The rcu_segcblist_accelerate() function returns true iff it is necessary
to request another grace period. A tracing session showed that this
function unnecessarily requests grace periods.
For example, consider the following sequence of events:
1. Callbacks are queued only on the NEXT segment of CPU A's callback list.
2. CPU A runs RCU_SOFTIRQ, accelerating these callbacks from NEXT to WAIT.
3. Thus rcu_segcblist_accelerate() returns true, requesting grace period N.
4. RCU's grace-period kthread wakes up on CPU B and starts grace period N.
4. CPU A notices the new grace period and invokes RCU_SOFTIRQ.
5. CPU A's RCU_SOFTIRQ again invokes rcu_segcblist_accelerate(), but
there are no new callbacks. However, rcu_segcblist_accelerate()
nevertheless (uselessly) requests a new grace period N+1.
This extra grace period results in additional lock contention and also
additional wakeups, all for no good reason.
This commit therefore adds a check to rcu_segcblist_accelerate() that
prevents the return of true when there are no new callbacks.
This change reduces the number of grace periods (GPs) and wakeups in each
of eleven five-second rcutorture runs as follows:
+----+-------------------+-------------------+
| # | Number of GPs | Number of Wakeups |
+====+=========+=========+=========+=========+
| 1 | With | Without | With | Without |
+----+---------+---------+---------+---------+
| 2 | 75 | 89 | 113 | 119 |
+----+---------+---------+---------+---------+
| 3 | 62 | 91 | 105 | 123 |
+----+---------+---------+---------+---------+
| 4 | 60 | 79 | 98 | 110 |
+----+---------+---------+---------+---------+
| 5 | 63 | 79 | 99 | 112 |
+----+---------+---------+---------+---------+
| 6 | 57 | 89 | 96 | 123 |
+----+---------+---------+---------+---------+
| 7 | 64 | 85 | 97 | 118 |
+----+---------+---------+---------+---------+
| 8 | 58 | 83 | 98 | 113 |
+----+---------+---------+---------+---------+
| 9 | 57 | 77 | 89 | 104 |
+----+---------+---------+---------+---------+
| 10 | 66 | 82 | 98 | 119 |
+----+---------+---------+---------+---------+
| 11 | 52 | 82 | 83 | 117 |
+----+---------+---------+---------+---------+
The reduction in the number of wakeups ranges from 5% to 40%.
Cc: urezki@gmail.com
[ paulmck: Rework commit log and comment. ]
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Mon, 17 Aug 2020 23:44:48 +0000 (16:44 -0700)]
torture: Add gdb support
This commit adds a "--gdb" parameter to kvm.sh, which causes
"CONFIG_DEBUG_INFO=y" to be added to the Kconfig options, "nokaslr"
to be added to the boot parameters, and "-s -S" to be added to the qemu
arguments. Furthermore, the scripting prints messages telling the user
how to start up gdb for the run in question.
Because of the interactive nature of gdb sessions, only one "--configs"
scenario is permitted when "--gdb" is specified. For most torture types,
this means that a "--configs" argument is required, and that argument
must specify the single scenario of interest.
The usual cautions about breakpoints and timing apply, for example,
staring at your gdb prompt for too long will likely get you many
complaints, including RCU CPU stall warnings. Omar Sandoval further
suggests using gdb's "hbreak" command instead of the "break" command on
systems supporting hardware breakpoints, and further using the "commands"
option because the resulting non-interactive breakpoints are less likely
to get you RCU CPU stall warnings.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Tue, 11 Aug 2020 17:33:39 +0000 (10:33 -0700)]
rcutorture: Allow pointer leaks to test diagnostic code
This commit adds an rcutorture.leakpointer module parameter that
intentionally leaks an RCU-protected pointer out of the RCU read-side
critical section and checks to see if the corresponding grace period
has elapsed, emitting a WARN_ON_ONCE() if so. This module parameter can
be used to test facilities like CONFIG_RCU_STRICT_GRACE_PERIOD that end
grace periods quickly.
While in the area, also document rcutorture.irqreader, which was
previously left out.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 22 Jul 2020 17:45:12 +0000 (10:45 -0700)]
rcutorture: Hoist OOM registry up one level
Currently, registering and unregistering the OOM notifier is done
right before and after the test, respectively. This will not work
well for multi-threaded tests, so this commit hoists this registering
and unregistering up into the rcu_torture_fwd_prog_init() and
rcu_torture_fwd_prog_cleanup() functions.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Colin Ian King [Thu, 16 Jul 2020 14:38:56 +0000 (15:38 +0100)]
refperf: Avoid null pointer dereference when buf fails to allocate
Currently in the unlikely event that buf fails to be allocated it
is dereferenced a few times. Use the errexit flag to determine if
buf should be written to to avoid the null pointer dereferences.
Addresses-Coverity: ("Dereference after null check")
Fixes:
f518f154ecef ("refperf: Dynamically allocate experiment-summary output buffer")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Mon, 20 Jul 2020 15:34:07 +0000 (08:34 -0700)]
rcutorture: Properly synchronize with OOM notifier
The current rcutorture forward-progress code assumes that it is the
only cause of out-of-memory (OOM) events. For script-based rcutorture
testing, this assumption is in fact correct. However, testing based
on modprobe/rmmod might well encounter external OOM events, which could
happen at any time.
This commit therefore properly synchronizes the interaction between
rcutorture's forward-progress testing and its OOM notifier by adding a
global mutex.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Sun, 19 Jul 2020 21:40:31 +0000 (14:40 -0700)]
rcutorture: Properly set rcu_fwds for OOM handling
The conversion of rcu_fwds to dynamic allocation failed to actually
allocate the required structure. This commit therefore allocates it,
frees it, and updates rcu_fwds accordingly. While in the area, it
abstracts the cleanup actions into rcu_torture_fwd_prog_cleanup().
Fixes:
5155be9994e5 ("rcutorture: Dynamically allocate rcu_fwds structure")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Sun, 19 Jul 2020 19:17:53 +0000 (12:17 -0700)]
torture: Add kvm.sh --help and update help message
This commit adds a --help argument (along with its synonym -h) to display
the help text. While in the area, this commit also updates the help text.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Tue, 14 Jul 2020 18:02:15 +0000 (11:02 -0700)]
rcutorture: Add CONFIG_PROVE_RCU_LIST to TREE05
Currently, the CONFIG_PROVE_RCU_LIST=y case is untested. This commit
therefore adds CONFIG_PROVE_RCU_LIST=y to rcutorture's TREE05 scenario.
Cc: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Mon, 13 Jul 2020 21:18:33 +0000 (14:18 -0700)]
torture: Update initrd documentation
The rcu-test-image.txt documentation covers a very uncommon case where
a real userspace environment is required. However, someone reading this
document might reasonably conclude that this is in fact a prerequisite.
In addition, the initrd.txt file mentions dracut, which is no longer used.
This commit therefore provides the needed updates.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Alexander A. Klimov [Mon, 13 Jul 2020 19:37:06 +0000 (21:37 +0200)]
rcutorture: Replace HTTP links with HTTPS ones
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Wei Yongjun [Fri, 3 Jul 2020 05:05:27 +0000 (13:05 +0800)]
locktorture: Make function torture_percpu_rwsem_init() static
The sparse tool complains as follows:
kernel/locking/locktorture.c:569:6: warning:
symbol 'torture_percpu_rwsem_init' was not declared. Should it be static?
And this function is not used outside of locktorture.c,
so this commit marks it static.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul Gortmaker [Thu, 2 Jul 2020 22:59:05 +0000 (15:59 -0700)]
torture: document --allcpus argument added to the kvm.sh script
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Joel Fernandes (Google) [Thu, 18 Jun 2020 20:29:55 +0000 (16:29 -0400)]
rcutorture: Output number of elapsed grace periods
This commit adds code to print the grace-period number at the start
of the test along with both the grace-period number and the number of
elapsed grace periods at the end of the test. Note that variants of
RCU)without the notion of a grace-period number (for example, Tiny RCU)
just print zeroes.
[ paulmck: Adjust commit log. ]
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 17 Jun 2020 20:22:17 +0000 (13:22 -0700)]
rcutorture: Remove KCSAN stubs
KCSAN is now in mainline, so this commit removes the stubs for the
data_race(), ASSERT_EXCLUSIVE_WRITER(), and ASSERT_EXCLUSIVE_ACCESS()
macros.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 20 Aug 2020 18:26:14 +0000 (11:26 -0700)]
rcu: Remove unused "cpu" parameter from rcu_report_qs_rdp()
The "cpu" parameter to rcu_report_qs_rdp() is not used, with rdp->cpu
being used instead. Furtheremore, every call to rcu_report_qs_rdp()
invokes it on rdp->cpu. This commit therefore removes this unused "cpu"
parameter and converts a check of rdp->cpu against smp_processor_id()
to a WARN_ON_ONCE().
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Mon, 10 Aug 2020 16:58:03 +0000 (09:58 -0700)]
rcu: Report QS for outermost PREEMPT=n rcu_read_unlock() for strict GPs
The CONFIG_PREEMPT=n instance of rcu_read_unlock is even more
aggressively than that of CONFIG_PREEMPT=y in deferring reporting
quiescent states to the RCU core. This is just what is wanted in normal
use because it reduces overhead, but the resulting delay is not what
is wanted for kernels built with CONFIG_RCU_STRICT_GRACE_PERIOD=y.
This commit therefore adds an rcu_read_unlock_strict() function that
checks for exceptional conditions, and reports the newly started
quiescent state if it is safe to do so, also doing a spin-delay if
requested via rcutree.rcu_unlock_delay. This commit also adds a call
to rcu_read_unlock_strict() from the CONFIG_PREEMPT=n instance of
__rcu_read_unlock().
[ paulmck: Fixed bug located by kernel test robot <lkp@intel.com> ]
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Sat, 8 Aug 2020 14:56:31 +0000 (07:56 -0700)]
rcu: Execute RCU reader shortly after rcu_core for strict GPs
A kernel built with CONFIG_RCU_STRICT_GRACE_PERIOD=y needs a quiescent
state to appear very shortly after a CPU has noticed a new grace period.
Placing an RCU reader immediately after this point is ineffective because
this normally happens in softirq context, which acts as a big RCU reader.
This commit therefore introduces a new per-CPU work_struct, which is
used at the end of rcu_core() processing to schedule an RCU read-side
critical section from within a clean environment.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 7 Aug 2020 20:44:10 +0000 (13:44 -0700)]
rcu: Provide optional RCU-reader exit delay for strict GPs
The goal of this series is to increase the probability of tools like
KASAN detecting that an RCU-protected pointer was used outside of its
RCU read-side critical section. Thus far, the approach has been to make
grace periods and callback processing happen faster. Another approach
is to delay the pointer leaker. This commit therefore allows a delay
to be applied to exit from RCU read-side critical sections.
This slowdown is specified by a new rcutree.rcu_unlock_delay kernel boot
parameter that specifies this delay in microseconds, defaulting to zero.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 7 Aug 2020 02:42:47 +0000 (19:42 -0700)]
rcu: IPI all CPUs at GP end for strict GPs
Currently, each CPU discovers the end of a given grace period on its
own time, which is again good for efficiency but bad for fast grace
periods, given that it is things like kfree() within the RCU callbacks
that will cause trouble for pointers leaked from RCU read-side critical
sections. This commit therefore uses on_each_cpu() to IPI each CPU
after grace-period cleanup in order to inform each CPU of the end of
the old grace period in a timely manner, but only in kernels build with
CONFIG_RCU_STRICT_GRACE_PERIOD=y.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 7 Aug 2020 02:21:48 +0000 (19:21 -0700)]
rcu: IPI all CPUs at GP start for strict GPs
Currently, each CPU discovers the beginning of a given grace period
on its own time, which is again good for efficiency but bad for fast
grace periods. This commit therefore uses on_each_cpu() to IPI each
CPU after grace-period initialization in order to inform each CPU of
the new grace period in a timely manner, but only in kernels build with
CONFIG_RCU_STRICT_GRACE_PERIOD=y.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 6 Aug 2020 23:35:08 +0000 (16:35 -0700)]
rcu: Attempt QS when CPU discovers GP for strict GPs
A given CPU normally notes a new grace period during one RCU_SOFTIRQ,
but avoids reporting the corresponding quiescent state until some later
RCU_SOFTIRQ. This leisurly approach improves efficiency by increasing
the number of update requests served by each grace period, but is not
what is needed for kernels built with CONFIG_RCU_STRICT_GRACE_PERIOD=y.
This commit therefore adds a new rcu_strict_gp_check_qs() function
which, in CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels, simply enters and
immediately exist an RCU read-side critical section. If the CPU is
in a quiescent state, the rcu_read_unlock() will attempt to report an
immediate quiescent state. This rcu_strict_gp_check_qs() function is
invoked from note_gp_changes(), so that a CPU just noticing a new grace
period might immediately report a quiescent state for that grace period.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 6 Aug 2020 22:12:50 +0000 (15:12 -0700)]
rcu: Do full report for .need_qs for strict GPs
The rcu_preempt_deferred_qs_irqrestore() function is invoked at
the end of an RCU read-side critical section (for example, directly
from rcu_read_unlock()) and, if .need_qs is set, invokes rcu_qs() to
report the new quiescent state. This works, except that rcu_qs() only
updates per-CPU state, leaving reporting of the actual quiescent state
to a later call to rcu_report_qs_rdp(), for example from within a later
RCU_SOFTIRQ instance. Although this approach is exactly what you want if
you are more concerned about efficiency than about short grace periods,
in CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels, short grace periods are
the name of the game.
This commit therefore makes rcu_preempt_deferred_qs_irqrestore() directly
invoke rcu_report_qs_rdp() in CONFIG_RCU_STRICT_GRACE_PERIOD=y, thus
shortening grace periods.
Historical note: To the best of my knowledge, causing rcu_read_unlock()
to directly report a quiescent state first appeared in Jim Houston's
and Joe Korty's JRCU. This is the second instance of a Linux-kernel RCU
feature being inspired by JRCU, the first being RCU callback offloading
(as in the RCU_NOCB_CPU Kconfig option).
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 6 Aug 2020 16:40:18 +0000 (09:40 -0700)]
rcu: Always set .need_qs from __rcu_read_lock() for strict GPs
The ->rcu_read_unlock_special.b.need_qs field in the task_struct
structure indicates that the RCU core needs a quiscent state from the
corresponding task. The __rcu_read_unlock() function checks this (via
an eventual call to rcu_preempt_deferred_qs_irqrestore()), and if set
reports a quiscent state immediately upon exit from the outermost RCU
read-side critical section.
Currently, this flag is only set when the scheduling-clock interrupt
decides that the current RCU grace period is too old, as in about
one full second too old. But if the kernel has been built with
CONFIG_RCU_STRICT_GRACE_PERIOD=y, we clearly do not want to wait that
long. This commit therefore sets the .need_qs field immediately at the
start of the RCU read-side critical section from within __rcu_read_lock()
in order to unconditionally enlist help from __rcu_read_unlock().
But note the additional check for rcu_state.gp_kthread, which prevents
attempts to awaken RCU's grace-period kthread during early boot before
there is a scheduler. Leaving off this check results in early boot hangs.
So early that there is no console output. Thus, this additional check
fails until such time as RCU's grace-period kthread has been created,
avoiding these empty-console hangs.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 6 Aug 2020 13:39:30 +0000 (06:39 -0700)]
rcu: Force DEFAULT_RCU_BLIMIT to 1000 for strict RCU GPs
The value of DEFAULT_RCU_BLIMIT is normally set to 10, the idea being to
avoid needless response-time degradation due to RCU callback invocation.
However, when CONFIG_RCU_STRICT_GRACE_PERIOD=y it is better to avoid
throttling callback execution in order to better detect pointer
leaks from RCU read-side critical sections. This commit therefore
sets the value of DEFAULT_RCU_BLIMIT to 1000 in kernels built with
CONFIG_RCU_STRICT_GRACE_PERIOD=y.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 6 Aug 2020 00:25:23 +0000 (17:25 -0700)]
rcu: Restrict default jiffies_till_first_fqs for strict RCU GPs
If there are idle CPUs, RCU's grace-period kthread will wait several
jiffies before even thinking about polling them. This promotes
efficiency, which is normally a good thing, but when the kernel
has been built with CONFIG_RCU_STRICT_GRACE_PERIOD=y, we care more
about short grace periods. This commit therefore restricts the
default jiffies_till_first_fqs value to zero in kernels built with
CONFIG_RCU_STRICT_GRACE_PERIOD=y, which causes RCU's grace-period kthread
to poll for idle CPUs immediately after starting a grace period.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 5 Aug 2020 23:52:17 +0000 (16:52 -0700)]
rcu: Reduce leaf fanout for strict RCU grace periods
Because strict RCU grace periods will complete more quickly, they will
experience greater lock contention on each leaf rcu_node structure's
->lock. This commit therefore reduces the leaf fanout in order to reduce
this lock contention.
Note that this also has the effect of reducing the number of CPUs
supported to 16 in the case of CONFIG_RCU_FANOUT_LEAF=2 or 81 in the
case of CONFIG_RCU_FANOUT_LEAF=3. However, greater numbers of CPUs are
probably a bad idea when using CONFIG_RCU_STRICT_GRACE_PERIOD=y. Those
wishing to live dangerously are free to edit their kernel/rcu/Kconfig
files accordingly.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 5 Aug 2020 22:51:20 +0000 (15:51 -0700)]
rcu: Add Kconfig option for strict RCU grace periods
People running automated tests have asked for a way to make RCU minimize
grace-period duration in order to increase the probability of KASAN
detecting a pointer being improperly leaked from an RCU read-side critical
section, for example, like this:
rcu_read_lock();
p = rcu_dereference(gp);
do_something_with(p); // OK
rcu_read_unlock();
do_something_else_with(p); // BUG!!!
The rcupdate.rcu_expedited boot parameter is a start in this direction,
given that it makes calls to synchronize_rcu() instead invoke the faster
(and more wasteful) synchronize_rcu_expedited(). However, this does
nothing to shorten RCU grace periods that are instead initiated by
call_rcu(), and RCU pointer-leak bugs can involve call_rcu() just as
surely as they can synchronize_rcu().
This commit therefore adds a RCU_STRICT_GRACE_PERIOD Kconfig option
that will be used to shorten normal (non-expedited) RCU grace periods.
This commit also dumps out a message when this option is in effect.
Later commits will actually shorten grace periods.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 12 Aug 2020 04:18:12 +0000 (21:18 -0700)]
rcuperf: Change rcuperf to rcuscale
This commit further avoids conflation of rcuperf with the kernel's perf
feature by renaming kernel/rcu/rcuperf.c to kernel/rcu/rcuscale.c, and
also by similarly renaming the functions and variables inside this file.
This has the side effect of changing the names of the kernel boot
parameters, so kernel-parameters.txt and ver_functions.sh are also
updated. The rcutorture --torture type was also updated from rcuperf
to rcuscale.
[ paulmck: Fix bugs located by Stephen Rothwell. ]
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 23 Jul 2020 22:53:02 +0000 (15:53 -0700)]
scftorture: Add cond_resched() to test loop
Although the test loop does randomly delay, which would provide quiescent
states and so forth, it is possible for there to be a series of long
smp_call_function*() handler runtimes with no delays, which results in
softlockup and RCU CPU stall warning messages. This commit therefore
inserts a cond_resched() into the main test loop.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 3 Jul 2020 22:23:19 +0000 (15:23 -0700)]
scftorture: Adapt memory-ordering test to UP operation
On uniprocessor systems, smp_call_function() does nothing. This commit
therefore avoids complaining about the lack of handler accesses in the
single-CPU case where there is no handler.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 2 Jul 2020 21:15:33 +0000 (14:15 -0700)]
scftorture: Block scftorture_invoker() kthreads for offline CPUs
Currently, CPU-hotplug operations might result in all but two
of (say) 100 CPUs being offline, which in turn might result in
false-positive diagnostics due to overload. This commit therefore
causes scftorture_invoker() kthreads for offline CPUs to loop blocking
for 200 milliseconds at a time, thus continuously adjusting the number
of threads to match the number of online CPUs.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 2 Jul 2020 19:15:37 +0000 (12:15 -0700)]
scftorture: Check unexpected "switch" statement value
This commit adds a "default" case to the switch statement in
scftorture_invoke_one() which contains a WARN_ON_ONCE() and an assignment
to ->scfc_out to suppress knock-on warnings. These knock-on warnings
could otherwise cause the user to think that there was a memory-ordering
problem in smp_call_function() instead of a bug in scftorture.c itself.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Wei Yongjun [Thu, 2 Jul 2020 16:56:50 +0000 (09:56 -0700)]
scftorture: Make symbol 'scf_torture_rand' static
The sparse tool complains as follows
kernel/scftorture.c:124:1: warning:
symbol '__pcpu_scope_scf_torture_rand' was not declared. Should it be static?
And this per-CPU variable is not used outside of scftorture.c,
so this commit marks it static.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 1 Jul 2020 23:38:16 +0000 (16:38 -0700)]
scftorture: Prevent compiler from reducing race probabilities
Detecting smp_call_function() memory misordering requires close timing,
so it is necessary to have the checks immediately before and after
the call to the smp_call_function*() function under test. This commit
therefore inserts barrier() calls to prevent the compiler from optimizing
memory-misordering detection down into the zone of extreme improbability.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 1 Jul 2020 23:06:22 +0000 (16:06 -0700)]
scftorture: Flag errors in torture-compatible manner
This commit prints error counts on the statistics line and also adds a
"!!!" if any of the counters are non-zero. Allocation failures are
(somewhat) forgiven, but all other errors result in a "FAILURE" print
at the end of the test.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 9 Jul 2020 20:58:32 +0000 (13:58 -0700)]
scftorture: Consolidate scftorture_invoke_one() scf_check initialization
This commit hoists much of the initialization of the scf_check
structure out of the switch statement, thus saving a few lines of code.
The initialization of the ->scfc_in field remains in each leg of the
switch statement in order to more heavily stress memory ordering.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 1 Jul 2020 21:13:02 +0000 (14:13 -0700)]
scftorture: Consolidate scftorture_invoke_one() check and kfree()
This commit moves checking of the ->scfc_out field and the freeing of
the scf_check structure down below the end of switch statement, thus
saving a few lines of code.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 1 Jul 2020 20:49:06 +0000 (13:49 -0700)]
scftorture: Add smp_call_function() memory-ordering checks
This commit adds checks for memory misordering across calls to and
returns from smp_call_function() in the case where the caller waits.
Misordering results in a splat.
Note that in contrast to smp_call_function_single(), this code does not
test memory ordering into the handler in the no-wait case because none
of the handlers would be able to free the scf_check structure without
introducing heavy synchronization to work out which was last.
[ paulmck: s/GFP_KERNEL/GFP_ATOMIC/ per kernel test robot feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 1 Jul 2020 19:30:02 +0000 (12:30 -0700)]
scftorture: Add smp_call_function_many() memory-ordering checks
This commit adds checks for memory misordering across calls to and
returns from smp_call_function_many() in the case where the caller waits.
Misordering results in a splat.
Note that in contrast to smp_call_function_single(), this code does not
test memory ordering into the handler in the no-wait case because none
of the handlers would be able to free the scf_check structure without
introducing heavy synchronization to work out which was last.
[ paulmck: s/GFP_KERNEL/GFP_ATOMIC/ per kernel test robot feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 1 Jul 2020 03:49:50 +0000 (20:49 -0700)]
scftorture: Add smp_call_function_single() memory-ordering checks
This commit adds checks for memory misordering across calls to
smp_call_function_single() and also across returns in the case where
the caller waits. Misordering results in a splat.
[ paulmck: s/GFP_KERNEL/GFP_ATOMIC/ per kernel test robot feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Tue, 30 Jun 2020 23:13:37 +0000 (16:13 -0700)]
scftorture: Summarize per-thread statistics
This commit summarizes the per-thread statistics, providing counts of
the number of single, many, and all calls, both no-wait and wait, and,
for the single case, the number where the target CPU was offline.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 26 Jun 2020 20:39:41 +0000 (13:39 -0700)]
tick-sched: Clarify "NOHZ: local_softirq_pending" warning
Currently, can_stop_idle_tick() prints "NOHZ: local_softirq_pending HH"
(where "HH" is the hexadecimal softirq vector number) when one or more
non-RCU softirq handlers are still enabled when checking to stop the
scheduler-tick interrupt. This message is not as enlightening as one
might hope, so this commit changes it to "NOHZ tick-stop error: Non-RCU
local softirq work is pending, handler #HH".
Reported-by: Andy Lutomirski <luto@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Fri, 26 Jun 2020 00:05:58 +0000 (17:05 -0700)]
scftorture: Implement weighted primitive selection
This commit uses the scftorture.weight* kernel parameters to randomly
chooses between smp_call_function_single(), smp_call_function_many(),
and smp_call_function(). For each variant, it also randomly chooses
whether to invoke it synchronously (wait=1) or asynchronously (wait=0).
The percentage weighting for each option are dumped to the console log
(search for "scf_sel_dump").
This accumulates statistics, which a later commit will dump out at the
end of the run.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 25 Jun 2020 00:57:07 +0000 (17:57 -0700)]
torture: Add scftorture to the rcutorture scripting
This commit updates the rcutorture scripting to include the new scftorture
torture-test module.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Tue, 30 Jun 2020 20:37:22 +0000 (13:37 -0700)]
torture: Declare parse-console.sh independence from rcutorture
Currently, parse-torture.sh looks at the fifth field of torture-test
console output for the version number. This works fine for rcutorture,
but not for scftorture, which lacks the pointer field. This commit
therefore adjusts matching lines so that the parse-console.sh awk script
always sees the version number as the first field in the lines passed
to it.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 24 Jun 2020 22:59:59 +0000 (15:59 -0700)]
scftorture: Add smp_call_function() torture test
This commit adds an smp_call_function() torture test that repeatedly
invokes this function and complains if things go badly awry.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Mon, 17 Aug 2020 17:37:22 +0000 (10:37 -0700)]
rcu: Remove unused __rcu_is_watching() function
The x86/entry work removed all uses of __rcu_is_watching(), therefore
this commit removes it entirely.
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <x86@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Joel Fernandes (Google) [Fri, 7 Aug 2020 17:07:20 +0000 (13:07 -0400)]
rcu: Make FQS more aggressive in complaining about offline CPUs
The RCU grace-period kthread's force-quiescent state (FQS) loop should
never see an offline CPU that has not yet reported a quiescent state.
After all, the offline CPU should have reported a quiescent state
during the CPU-offline process, or, failing that, by rcu_gp_init()
if it ran concurrently with either the CPU going offline or the last
task on a leaf rcu_node structure exiting its RCU read-side critical
section while all CPUs corresponding to that structure are offline.
The FQS loop should therefore complain if it does see an offline CPU
that has not yet reported a quiescent state.
And it does, but only once the grace period has been in force for a
full second. This commit therefore makes this warning more aggressive,
so that it will trigger as soon as the condition makes its appearance.
Light testing with TREE03 and hotplug shows no warnings. This commit
also converts the warning to WARN_ON_ONCE() in order to stave off possible
log spam.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Joel Fernandes (Google) [Fri, 7 Aug 2020 17:07:19 +0000 (13:07 -0400)]
rcu: Clarify comments about FQS loop reporting quiescent states
Since at least v4.19, the FQS loop no longer reports quiescent states
for offline CPUs except in emergency situations.
This commit therefore fixes the comment in rcu_gp_init() to match the
current code.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 5 Aug 2020 17:35:16 +0000 (10:35 -0700)]
rcu/nocb: Add a warning for non-GP kthread running GP code
This commit increases RCU's ability to defend itself by emitting a warning
if one of the nocb CB kthreads invokes the GP kthread's wait function.
This warning augments a similar check that is carried out at the end
of rcutorture testing and when RCU CPU stall warnings are emitted.
The problem with those checks is that the miscreants have long since
departed and disposed of any and all evidence.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Sat, 25 Jul 2020 03:22:05 +0000 (20:22 -0700)]
rcu: Move rcu_cpu_started per-CPU variable to rcu_data
When the rcu_cpu_started per-CPU variable was added by commit
f64c6013a202 ("rcu/x86: Provide early rcu_cpu_starting() callback"),
there were multiple sets of per-CPU rcu_data structures. Therefore, the
rcu_cpu_started flag was added as a separate per-CPU variable. But now
there is only one set of per-CPU rcu_data structures, so this commit
moves rcu_cpu_started to a new ->cpu_started field in that structure.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Madhuparna Bhowmik [Sun, 12 Jul 2020 13:10:03 +0000 (18:40 +0530)]
kvm: mmu: page_track: Fix RCU list API usage
Use hlist_for_each_entry_srcu() instead of hlist_for_each_entry_rcu()
as it also checkes if the right lock is held.
Using hlist_for_each_entry_rcu() with a condition argument will not
report the cases where a SRCU protected list is traversed using
rcu_read_lock(). Hence, use hlist_for_each_entry_srcu().
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: <kvm@vger.kernel.org>
Madhuparna Bhowmik [Sun, 12 Jul 2020 13:10:02 +0000 (18:40 +0530)]
rculist: Introduce list/hlist_for_each_entry_srcu() macros
list/hlist_for_each_entry_rcu() provides an optional cond argument
to specify the lock held in the updater side.
However for SRCU read side, not providing the cond argument results
into false positive as whether srcu_read_lock is held or not is not
checked implicitly. Therefore, on read side the lockdep expression
srcu_read_lock_held(srcu struct) can solve this issue.
However, the function still fails to check the cases where srcu
protected list is traversed with rcu_read_lock() instead of
srcu_read_lock(). Therefore, to remove the false negative,
this patch introduces two new list traversal primitives :
list_for_each_entry_srcu() and hlist_for_each_entry_srcu().
Both of the functions have non-optional cond argument
as it is required for both read and update side, and simply checks
if the cond is true. For regular read side the lockdep expression
srcu_read_lock_head() can be passed as the cond argument to
list/hlist_for_each_entry_srcu().
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Suraj Upadhyay <usuraj35@gmail.com>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
[ paulmck: Add "true" per kbuild test robot feedback. ]
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Tobias Klauser [Thu, 9 Jul 2020 13:05:59 +0000 (15:05 +0200)]
rcu: Fix kerneldoc comments in rcupdate.h
This commit fixes the kerneldoc comments for rcu_read_unlock_bh(),
rcu_read_unlock_sched() and rcu_head_after_call_rcu() so they e.g. get
properly linked in the API documentation. Also add parenthesis after
function names to match the notation used in other kerneldoc comments in
the same file.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 24 Jun 2020 03:57:59 +0000 (20:57 -0700)]
rcu: Add READ_ONCE() to rcu_do_batch() access to rcu_cpu_stall_ftrace_dump
Given that sysfs can change the value of rcu_cpu_stall_ftrace_dump at any
time, this commit adds a READ_ONCE() to the accesses to that variable.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 24 Jun 2020 01:04:45 +0000 (18:04 -0700)]
rcu: Add READ_ONCE() to rcu_do_batch() access to rcu_kick_kthreads
Given that sysfs can change the value of rcu_kick_kthreads at any time,
this commit adds a READ_ONCE() to the sole access to that variable.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 24 Jun 2020 00:49:40 +0000 (17:49 -0700)]
rcu: Add READ_ONCE() to rcu_do_batch() access to rcu_resched_ns
Given that sysfs can change the value of rcu_resched_ns at any time,
this commit adds a READ_ONCE() to the sole access to that variable.
While in the area, this commit also adds bounds checking, clamping the
value to at least a millisecond, but no longer than a second.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 24 Jun 2020 00:09:27 +0000 (17:09 -0700)]
rcu: Add READ_ONCE() to rcu_do_batch() access to rcu_divisor
Given that sysfs can change the value of rcu_divisor at any time, this
commit adds a READ_ONCE to the sole access to that variable. While in
the area, this commit also adds bounds checking, clamping the value to
a shift that makes sense for a signed long.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Mon, 22 Jun 2020 23:46:43 +0000 (16:46 -0700)]
nocb: Remove show_rcu_nocb_state() false positive printout
The rcu_data structure's ->nocb_timer field is used to defer wakeups of
the corresponding no-CBs CPU's grace-period kthread ("rcuog*"), and that
structure's ->nocb_defer_wakeup field is used to track such deferral.
This means that the show_rcu_nocb_state() printing an error when those
fields are set for a CPU not corresponding to a no-CBs grace-period
kthread is erroneous.
This commit therefore switches the check from ->nocb_timer to
->nocb_bypass_timer and removes the check of ->nocb_defer_wakeup.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Neeraj Upadhyay [Mon, 22 Jun 2020 18:07:03 +0000 (23:37 +0530)]
rcu/tree: Remove CONFIG_PREMPT_RCU check in force_qs_rnp()
Originally, the call to rcu_preempt_blocked_readers_cgp() from
force_qs_rnp() had to be conditioned on CONFIG_PREEMPT_RCU=y, as in
commit
a77da14ce9af ("rcu: Yet another fix for preemption and CPU
hotplug"). However, there is now a CONFIG_PREEMPT_RCU=n definition of
rcu_preempt_blocked_readers_cgp() that unconditionally returns zero, so
invoking it is now safe. In addition, the CONFIG_PREEMPT_RCU=n definition
of rcu_initiate_boost() simply releases the rcu_node structure's ->lock,
which is what happens when the "if" condition evaluates to false.
This commit therefore drops the IS_ENABLED(CONFIG_PREEMPT_RCU) check,
so that rcu_initiate_boost() is called only in CONFIG_PREEMPT_RCU=y
kernels when there are readers blocking the current grace period.
This does not change the behavior, but reduces code-reader confusion by
eliminating non-CONFIG_PREEMPT_RCU=y calls to rcu_initiate_boost().
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Neeraj Upadhyay [Sun, 21 Jun 2020 18:37:27 +0000 (00:07 +0530)]
rcu/tree: Force quiescent state on callback overload
On callback overload, it is necessary to quickly detect idle CPUs,
and rcu_gp_fqs_check_wake() checks for this condition. Unfortunately,
the code following the call to this function does not repeat this check,
which means that in reality no actual quiescent-state forcing, instead
only a couple of quick and pointless wakeups at the beginning of the
grace period.
This commit therefore adds a check for the RCU_GP_FLAG_OVLD flag in
the post-wakeup "if" statement in rcu_gp_fqs_loop().
Fixes:
1fca4d12f4637 ("rcu: Expedite first two FQS scans under callback-overload conditions")
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Mon, 22 Jun 2020 16:25:34 +0000 (09:25 -0700)]
nocb: Clarify RCU nocb CPU error message
A message of the form "rcu: !!! lDTs ." can be tracked down, but
doing so is not trivial. This commit therefore eases this process by
adding text so that this error message now reads as follows:
"rcu: nocb GP activity on CB-only CPU!!! lDTs ."
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Joel Fernandes (Google) [Fri, 19 Jun 2020 01:36:40 +0000 (21:36 -0400)]
rcu/trace: Use gp_seq_req in acceleration's rcu_grace_period tracepoint
During acceleration of CB, the rsp's gp_seq is rcu_seq_snap'd. This is
the value used for acceleration - it is the value of gp_seq at which it
is safe the execute all callbacks in the callback list.
The rdp's gp_seq is not very useful for this scenario. Make
rcu_grace_period report the gp_seq_req instead as it allows one to
reason about how the acceleration works.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Joel Fernandes (Google) [Fri, 19 Jun 2020 01:36:39 +0000 (21:36 -0400)]
rcu/trace: Print negative GP numbers correctly
GP numbers start from -300 and gp_seq numbers start of -1200 (for a
shift of 2). These negative numbers are printed as unsigned long which
not only takes up more text space, but is rather confusing to the reader
as they have to constantly expend energy to truncate the number. Just
print the negative numbering directly.
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Thu, 18 Jun 2020 16:51:12 +0000 (09:51 -0700)]
rcu: Initialize at declaration time in rcu_exp_handler()
This commit moves the initialization of the CONFIG_PREEMPT=n version of
the rcu_exp_handler() function's rdp and rnp local variables into their
respective declarations to save a couple lines of code.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 17 Jun 2020 20:24:04 +0000 (13:24 -0700)]
srcu: Remove KCSAN stubs
KCSAN is now in mainline, so this commit removes the stubs for the
data_race(), ASSERT_EXCLUSIVE_WRITER(), and ASSERT_EXCLUSIVE_ACCESS()
macros.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 17 Jun 2020 20:26:20 +0000 (13:26 -0700)]
rcu: Remove KCSAN stubs from update.c
KCSAN is now in mainline, so this commit removes the stubs for the
data_race(), ASSERT_EXCLUSIVE_WRITER(), and ASSERT_EXCLUSIVE_ACCESS()
macros.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 17 Jun 2020 20:25:26 +0000 (13:25 -0700)]
rcu: Remove KCSAN stubs
KCSAN is now in mainline, so this commit removes the stubs for the
data_race(), ASSERT_EXCLUSIVE_WRITER(), and ASSERT_EXCLUSIVE_ACCESS()
macros.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Randy Dunlap [Fri, 3 Jul 2020 21:33:42 +0000 (14:33 -0700)]
doc: Drop doubled words from RCU requirements documentation
Drop the doubled words "to" and "for".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: rcu@vger.kernel.org
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Randy Dunlap [Fri, 3 Jul 2020 21:33:41 +0000 (14:33 -0700)]
doc: Drop doubled words from RCU Data-Structures.rst
Drop the doubled word "the".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: rcu@vger.kernel.org
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Tobias Klauser [Thu, 2 Jul 2020 16:28:10 +0000 (18:28 +0200)]
docs: Fix typo in synchronize_rcu() function name
s/sychronize_rcu/synchronize_rcu/
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Paul E. McKenney [Wed, 8 Jul 2020 23:25:43 +0000 (16:25 -0700)]
lib: Add backtrace_idle parameter to force backtrace of idle CPUs
Currently, the nmi_cpu_backtrace() declines to produce backtraces for
idle CPUs. This is a good choice in the common case in which problems are
caused only by non-idle CPUs. However, there are occasionally situations
in which idle CPUs are helping to cause problems. This commit therefore
adds an nmi_backtrace.backtrace_idle kernel boot parameter that causes
nmi_cpu_backtrace() to dump stacks even of idle CPUs.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <linux-doc@vger.kernel.org>
Linus Torvalds [Sun, 16 Aug 2020 20:04:57 +0000 (13:04 -0700)]
Linux 5.9-rc1
Linus Torvalds [Sun, 16 Aug 2020 17:55:12 +0000 (10:55 -0700)]
Merge tag 'io_uring-5.9-2020-08-15' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe:
"A few differerent things in here.
Seems like syzbot got some more io_uring bits wired up, and we got a
handful of reports and the associated fixes are in here.
General fixes too, and a lot of them marked for stable.
Lastly, a bit of fallout from the async buffered reads, where we now
more easily trigger short reads. Some applications don't really like
that, so the io_read() code now handles short reads internally, and
got a cleanup along the way so that it's now easier to read (and
documented). We're now passing tests that failed before"
* tag 'io_uring-5.9-2020-08-15' of git://git.kernel.dk/linux-block:
io_uring: short circuit -EAGAIN for blocking read attempt
io_uring: sanitize double poll handling
io_uring: internally retry short reads
io_uring: retain iov_iter state over io_read/io_write calls
task_work: only grab task signal lock when needed
io_uring: enable lookup of links holding inflight files
io_uring: fail poll arm on queue proc failure
io_uring: hold 'ctx' reference around task_work queue + execute
fs: RWF_NOWAIT should imply IOCB_NOIO
io_uring: defer file table grabbing request cleanup for locked requests
io_uring: add missing REQ_F_COMP_LOCKED for nested requests
io_uring: fix recursive completion locking on oveflow flush
io_uring: use TWA_SIGNAL for task_work uncondtionally
io_uring: account locked memory before potential error case
io_uring: set ctx sq/cq entry count earlier
io_uring: Fix NULL pointer dereference in loop_rw_iter()
io_uring: add comments on how the async buffered read retry works
io_uring: io_async_buf_func() need not test page bit
Mike Rapoport [Sun, 16 Aug 2020 14:24:03 +0000 (17:24 +0300)]
parisc: fix PMD pages allocation by restoring pmd_alloc_one()
Commit
1355c31eeb7e ("asm-generic: pgalloc: provide generic pmd_alloc_one()
and pmd_free_one()") converted parisc to use generic version of
pmd_alloc_one() but it missed the fact that parisc uses order-1 pages for
PMD.
Restore the original version of pmd_alloc_one() for parisc, just use
GFP_PGTABLE_KERNEL that implies __GFP_ZERO instead of GFP_KERNEL and
memset.
Fixes:
1355c31eeb7e ("asm-generic: pgalloc: provide generic pmd_alloc_one() and pmd_free_one()")
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Tested-by: Meelis Roos <mroos@linux.ee>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lkml.kernel.org/r/9f2b5ebd-e4a4-0fa1-6cd3-4b9f6892d1ad@linux.ee
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Sun, 16 Aug 2020 03:36:42 +0000 (20:36 -0700)]
Merge tag 'block-5.9-2020-08-14' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"A few fixes on the block side of things:
- Discard granularity fix (Coly)
- rnbd cleanups (Guoqing)
- md error handling fix (Dan)
- md sysfs fix (Junxiao)
- Fix flush request accounting, which caused an IO slowdown for some
configurations (Ming)
- Properly propagate loop flag for partition scanning (Lennart)"
* tag 'block-5.9-2020-08-14' of git://git.kernel.dk/linux-block:
block: fix double account of flush request's driver tag
loop: unset GENHD_FL_NO_PART_SCAN on LOOP_CONFIGURE
rnbd: no need to set bi_end_io in rnbd_bio_map_kern
rnbd: remove rnbd_dev_submit_io
md-cluster: Fix potential error pointer dereference in resize_bitmaps()
block: check queue's limits.discard_granularity in __blkdev_issue_discard()
md: get sysfs entry after redundancy attr group create
Linus Torvalds [Sun, 16 Aug 2020 01:54:42 +0000 (18:54 -0700)]
Merge tag 'riscv-for-linus-5.9-mw1' of git://git./linux/kernel/git/riscv/linux
Pull RISC-V fix from Palmer Dabbelt:
"I collected a single fix during the merge window: we managed to break
the early trap setup on !MMU, this fixes it"
* tag 'riscv-for-linus-5.9-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: Setup exception vector for nommu platform
Linus Torvalds [Sun, 16 Aug 2020 01:50:32 +0000 (18:50 -0700)]
Merge tag 'sh-for-5.9' of git://git.libc.org/linux-sh
Pull arch/sh updates from Rich Felker:
"Cleanup, SECCOMP_FILTER support, message printing fixes, and other
changes to arch/sh"
* tag 'sh-for-5.9' of git://git.libc.org/linux-sh: (34 commits)
sh: landisk: Add missing initialization of sh_io_port_base
sh: bring syscall_set_return_value in line with other architectures
sh: Add SECCOMP_FILTER
sh: Rearrange blocks in entry-common.S
sh: switch to copy_thread_tls()
sh: use the generic dma coherent remap allocator
sh: don't allow non-coherent DMA for NOMMU
dma-mapping: consolidate the NO_DMA definition in kernel/dma/Kconfig
sh: unexport register_trapped_io and match_trapped_io_handler
sh: don't include <asm/io_trapped.h> in <asm/io.h>
sh: move the ioremap implementation out of line
sh: move ioremap_fixed details out of <asm/io.h>
sh: remove __KERNEL__ ifdefs from non-UAPI headers
sh: sort the selects for SUPERH alphabetically
sh: remove -Werror from Makefiles
sh: Replace HTTP links with HTTPS ones
arch/sh/configs: remove obsolete CONFIG_SOC_CAMERA*
sh: stacktrace: Remove stacktrace_ops.stack()
sh: machvec: Modernize printing of kernel messages
sh: pci: Modernize printing of kernel messages
...
Jens Axboe [Sat, 15 Aug 2020 22:58:42 +0000 (15:58 -0700)]
io_uring: short circuit -EAGAIN for blocking read attempt
One case was missed in the short IO retry handling, and that's hitting
-EAGAIN on a blocking attempt read (eg from io-wq context). This is a
problem on sockets that are marked as non-blocking when created, they
don't carry any REQ_F_NOWAIT information to help us terminate them
instead of perpetually retrying.
Fixes:
227c0c9673d8 ("io_uring: internally retry short reads")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Sat, 15 Aug 2020 18:44:50 +0000 (11:44 -0700)]
io_uring: sanitize double poll handling
There's a bit of confusion on the matching pairs of poll vs double poll,
depending on if the request is a pure poll (IORING_OP_POLL_ADD) or
poll driven retry.
Add io_poll_get_double() that returns the double poll waitqueue, if any,
and io_poll_get_single() that returns the original poll waitqueue. With
that, remove the argument to io_poll_remove_double().
Finally ensure that wait->private is cleared once the double poll handler
has run, so that remove knows it's already been seen.
Cc: stable@vger.kernel.org # v5.8
Reported-by: syzbot+7f617d4a9369028b8a2c@syzkaller.appspotmail.com
Fixes:
18bceab101ad ("io_uring: allow POLL_ADD with double poll_wait() users")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Linus Torvalds [Sat, 15 Aug 2020 18:17:15 +0000 (11:17 -0700)]
Merge tag 'perf-tools-2020-08-14' of git://git./linux/kernel/git/acme/linux
Pull more perf tools updates from Arnaldo Carvalho de Melo:
"Fixes:
- Fixes for 'perf bench numa'.
- Always memset source before memcpy in 'perf bench mem'.
- Quote CC and CXX for their arguments to fix build in environments
using those variables to pass more than just the compiler names.
- Fix module symbol processing, addressing regression detected via
"perf test".
- Allow multiple probes in record+script_probe_vfs_getname.sh 'perf
test' entry.
Improvements:
- Add script to autogenerate socket family name id->string table from
copy of kernel header, used so far in 'perf trace'.
- 'perf ftrace' improvements to provide similar options for this
utility so that one can go from 'perf record', 'perf trace', etc to
'perf ftrace' just by changing the name of the subcommand.
- Prefer new "sched:sched_waking" trace event when it exists in 'perf
sched' post processing.
- Update POWER9 metrics to utilize other metrics.
- Fall back to querying debuginfod if debuginfo not found locally.
Miscellaneous:
- Sync various kvm headers with kernel sources"
* tag 'perf-tools-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (40 commits)
perf ftrace: Make option description initials all capital letters
perf build-ids: Fall back to debuginfod query if debuginfo not found
perf bench numa: Remove dead code in parse_nodes_opt()
perf stat: Update POWER9 metrics to utilize other metrics
perf ftrace: Add change log
perf: ftrace: Add set_tracing_options() to set all trace options
perf ftrace: Add option --tid to filter by thread id
perf ftrace: Add option -D/--delay to delay tracing
perf: ftrace: Allow set graph depth by '--graph-opts'
perf ftrace: Add support for trace option tracing_thresh
perf ftrace: Add option 'verbose' to show more info for graph tracer
perf ftrace: Add support for tracing option 'irq-info'
perf ftrace: Add support for trace option funcgraph-irqs
perf ftrace: Add support for trace option sleep-time
perf ftrace: Add support for tracing option 'func_stack_trace'
perf tools: Add general function to parse sublevel options
perf ftrace: Add option '--inherit' to trace children processes
perf ftrace: Show trace column header
perf ftrace: Add option '-m/--buffer-size' to set per-cpu buffer size
perf ftrace: Factor out function write_tracing_file_int()
...
Linus Torvalds [Sat, 15 Aug 2020 17:38:03 +0000 (10:38 -0700)]
Merge tag 'x86-urgent-2020-08-15' of git://git./linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Misc fixes and small updates all around the place:
- Fix mitigation state sysfs output
- Fix an FPU xstate/sxave code assumption bug triggered by
Architectural LBR support
- Fix Lightning Mountain SoC TSC frequency enumeration bug
- Fix kexec debug output
- Fix kexec memory range assumption bug
- Fix a boundary condition in the crash kernel code
- Optimize porgatory.ro generation a bit
- Enable ACRN guests to use X2APIC mode
- Reduce a __text_poke() IRQs-off critical section for the benefit of
PREEMPT_RT"
* tag 'x86-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/alternatives: Acquire pte lock with interrupts enabled
x86/bugs/multihit: Fix mitigation reporting when VMX is not in use
x86/fpu/xstate: Fix an xstate size check warning with architectural LBRs
x86/purgatory: Don't generate debug info for purgatory.ro
x86/tsr: Fix tsc frequency enumeration bug on Lightning Mountain SoC
kexec_file: Correctly output debugging information for the PT_LOAD ELF header
kexec: Improve & fix crash_exclude_mem_range() to handle overlapping ranges
x86/crash: Correct the address boundary of function parameters
x86/acrn: Remove redundant chars from ACRN signature
x86/acrn: Allow ACRN guest to use X2APIC mode
Linus Torvalds [Sat, 15 Aug 2020 17:36:40 +0000 (10:36 -0700)]
Merge tag 'sched-urgent-2020-08-15' of git://git./linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
"Two fixes: fix a new tracepoint's output value, and fix the formatting
of show-state syslog printouts"
* tag 'sched-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/debug: Fix the alignment of the show-state debug output
sched: Fix use of count for nr_running tracepoint
Linus Torvalds [Sat, 15 Aug 2020 17:34:24 +0000 (10:34 -0700)]
Merge tag 'perf-urgent-2020-08-15' of git://git./linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
"Misc fixes, an expansion of perf syscall access to CAP_PERFMON
privileged tools, plus a RAPL HW-enablement for Intel SPR platforms"
* tag 'perf-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/rapl: Add support for Intel SPR platform
perf/x86/rapl: Support multiple RAPL unit quirks
perf/x86/rapl: Fix missing psys sysfs attributes
hw_breakpoint: Remove unused __register_perf_hw_breakpoint() declaration
kprobes: Remove show_registers() function prototype
perf/core: Take over CAP_SYS_PTRACE creds to CAP_PERFMON capability
Linus Torvalds [Sat, 15 Aug 2020 17:32:18 +0000 (10:32 -0700)]
Merge tag 'locking-urgent-2020-08-15' of git://git./linux/kernel/git/tip/tip
Pull locking fixlets from Ingo Molnar:
"A documentation fix and a 'fallthrough' macro update"
* tag 'locking-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Convert to use the preferred 'fallthrough' macro
Documentation/locking/locktypes: Fix a typo
Linus Torvalds [Sat, 15 Aug 2020 15:34:36 +0000 (08:34 -0700)]
Merge tag '9p-for-5.9-rc1' of git://github.com/martinetd/linux
Pull 9p updates from Dominique Martinet:
- some code cleanup
- a couple of static analysis fixes
- setattr: try to pick a fid associated with the file rather than the
dentry, which might sometimes matter
* tag '9p-for-5.9-rc1' of git://github.com/martinetd/linux:
9p: Remove unneeded cast from memory allocation
9p: remove unused code in 9p
net/9p: Fix sparse endian warning in trans_fd.c
9p: Fix memory leak in v9fs_mount
9p: retrieve fid from file when file instance exist.
Linus Torvalds [Sat, 15 Aug 2020 15:31:39 +0000 (08:31 -0700)]
Merge tag '5.9-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs fixes from Steve French:
"Three small cifs/smb3 fixes, one for stable fixing mkdir path with
the 'idsfromsid' mount option"
* tag '5.9-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
SMB3: Fix mkdir when idsfromsid configured on mount
cifs: Convert to use the fallthrough macro
cifs: Fix an error pointer dereference in cifs_mount()
Linus Torvalds [Sat, 15 Aug 2020 15:26:55 +0000 (08:26 -0700)]
Merge tag 'nfs-for-5.9-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust:
"Stable fixes:
- pNFS: Don't return layout segments that are being used for I/O
- pNFS: Don't move layout segments off the active list when being used for I/O
Features:
- NFS: Add support for user xattrs through the NFSv4.2 protocol
- NFS: Allow applications to speed up readdir+statx() using AT_STATX_DONT_SYNC
- NFSv4.0 allow nconnect for v4.0
Bugfixes and cleanups:
- nfs: ensure correct writeback errors are returned on close()
- nfs: nfs_file_write() should check for writeback errors
- nfs: Fix getxattr kernel panic and memory overflow
- NFS: Fix the pNFS/flexfiles mirrored read failover code
- SUNRPC: dont update timeout value on connection reset
- freezer: Add unsafe versions of freezable_schedule_timeout_interruptible for NFS
- sunrpc: destroy rpc_inode_cachep after unregister_filesystem"
* tag 'nfs-for-5.9-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (32 commits)
NFS: Fix flexfiles read failover
fs: nfs: delete repeated words in comments
rpc_pipefs: convert comma to semicolon
nfs: Fix getxattr kernel panic and memory overflow
NFS: Don't return layout segments that are in use
NFS: Don't move layouts to plh_return_segs list while in use
NFS: Add layout segment info to pnfs read/write/commit tracepoints
NFS: Add tracepoints for layouterror and layoutstats.
NFS: Report the stateid + status in trace_nfs4_layoutreturn_on_close()
SUNRPC dont update timeout value on connection reset
nfs: nfs_file_write() should check for writeback errors
nfs: ensure correct writeback errors are returned on close()
NFSv4.2: xattr cache: get rid of cache discard work queue
NFS: remove redundant initialization of variable result
NFSv4.0 allow nconnect for v4.0
freezer: Add unsafe versions of freezable_schedule_timeout_interruptible for NFS
sunrpc: destroy rpc_inode_cachep after unregister_filesystem
NFSv4.2: add client side xattr caching.
NFSv4.2: hook in the user extended attribute handlers
NFSv4.2: add the extended attribute proc functions.
...
Linus Torvalds [Sat, 15 Aug 2020 15:25:41 +0000 (08:25 -0700)]
Merge tag 'edac_updates_for_5.9_pt2' of git://git./linux/kernel/git/ras/ras
Pull edac fix from Tony Luck:
"Fix for the ie31200 driver that missed the first pull"
* tag 'edac_updates_for_5.9_pt2' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
EDAC/ie31200: Fallback if host bridge device is already initialized
Linus Torvalds [Sat, 15 Aug 2020 15:19:58 +0000 (08:19 -0700)]
Merge tag 'devicetree-fixes-for-5.9' of git://git./linux/kernel/git/robh/linux
Pull devicetree fixes from Rob Herring:
"Another round of 'allOf' removals and whitespace clean-ups of schemas"
* tag 'devicetree-fixes-for-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
dt-bindings: Remove more cases of 'allOf' containing a '$ref'
dt-bindings: Whitespace clean-ups in schema files
Linus Torvalds [Sat, 15 Aug 2020 15:18:22 +0000 (08:18 -0700)]
Merge tag 'acpi-5.9-rc1-2' of git://git./linux/kernel/git/rafael/linux-pm
Pull more ACPI updates from Rafael Wysocki:
"Add new hardware support to the ACPI driver for AMD SoCs, the x86 clk
driver and the Designware i2c driver (changes from Akshu Agrawal and
Pu Wen)"
* tag 'acpi-5.9-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
clk: x86: Support RV architecture
ACPI: APD: Add a fmw property is_raven
clk: x86: Change name from ST to FCH
ACPI: APD: Change name from ST to FCH
i2c: designware: Add device HID for Hygon I2C controller