There is exactly one caller of getnstime_raw_and_real in the kernel,
which is the pps_get_ts function. This changes the caller and
the implementation to work on timespec64 types rather than timespec,
to avoid the time_t overflow on 32-bit architectures.
For consistency with the other new functions (ktime_get_seconds,
ktime_get_real_*, ...), I'm renaming the function to
ktime_get_raw_and_real_ts64.
We still need to convert from the internal 64-bit type to 32 bit
types in the caller, but this conversion is now pushed out from
getnstime_raw_and_real to pps_get_ts. A follow-up patch changes
the remaining pps code to completely avoid the conversion.
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
There is only one user of the hardpps function in the kernel, so
it makes sense to atomically change it over to using 64-bit
timestamps for y2038 safety. In the hardpps implementation,
we also need to change the pps_normtime structure, which is
similar to struct timespec and also requires a 64-bit
seconds portion.
This introduces two temporary variables in pps_kc_event() to
do the conversion, they will be removed again in the next step,
which seemed preferable to having a larger patch changing it
all at the same time.
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
ARM and ARM64 have almost identical code for migrating interrupts on
cpu hotunplug. Provide a generic version which can be used by both.
The new code addresses a shortcoming in the ARM[64] variants which
fails to update the affinity change in some cases. The solution for
this is to use the core function irq_do_set_affinity() instead of open
coding it.
[ tglx: Added copyright notice and license boilerplate. Rewrote
subject and changelog. ]
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: <linux-arm-kernel@lists.infradead.org>
Link: http://lkml.kernel.org/r/1443087135-17044-2-git-send-email-yangyingliang@huawei.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Per-IRQ directories in procfs are created only when a handler is first
added to the irqdesc, not when the irqdesc is created. In the case of
a shared IRQ, multiple tasks can race to create a directory. This
race condition seems to have been present forever, but is easier to
hit with async probing.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Link: http://lkml.kernel.org/r/1443266636.2004.2.camel@decadent.org.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
My system keeps crashing with below message. vmstat_update() schedules a delayed
work in current cpu and expects the work runs in the cpu.
schedule_delayed_work() is expected to make delayed work run in local cpu. The
problem is timer can be migrated with NO_HZ. __queue_work() queues work in
timer handler, which could run in a different cpu other than where the delayed
work is scheduled. The end result is the delayed work runs in different cpu.
The patch makes __queue_delayed_work records local cpu earlier. Where the timer
runs doesn't change where the work runs with the change.
[ 28.010131] ------------[ cut here ]------------
[ 28.010609] kernel BUG at ../mm/vmstat.c:1392!
[ 28.011099] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN
[ 28.011860] Modules linked in:
[ 28.012245] CPU: 0 PID: 289 Comm: kworker/0:3 Tainted: G W4.3.0-rc3+ #634
[ 28.013065] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153802- 04/01/2014
[ 28.014160] Workqueue: events vmstat_update
[ 28.014571] task: ffff880117682580 ti: ffff8800ba428000 task.ti: ffff8800ba428000
[ 28.015445] RIP: 0010:[<ffffffff8115f921>] [<ffffffff8115f921>]vmstat_update+0x31/0x80
[ 28.016282] RSP: 0018:ffff8800ba42fd80 EFLAGS: 00010297
[ 28.016812] RAX: 0000000000000000 RBX: ffff88011a858dc0 RCX:0000000000000000
[ 28.017585] RDX: ffff880117682580 RSI: ffffffff81f14d8c RDI:ffffffff81f4df8d
[ 28.018366] RBP: ffff8800ba42fd90 R08: 0000000000000001 R09:0000000000000000
[ 28.019169] R10: 0000000000000000 R11: 0000000000000121 R12:ffff8800baa9f640
[ 28.019947] R13: ffff88011a81e340 R14: ffff88011a823700 R15:0000000000000000
[ 28.020071] FS: 0000000000000000(0000) GS:ffff88011a800000(0000)knlGS:0000000000000000
[ 28.020071] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 28.020071] CR2: 00007ff6144b01d0 CR3: 00000000b8e93000 CR4:00000000000006f0
[ 28.020071] Stack:
[ 28.020071] ffff88011a858dc0 ffff8800baa9f640 ffff8800ba42fe00ffffffff8106bd88
[ 28.020071] ffffffff8106bd0b 0000000000000096 0000000000000000ffffffff82f9b1e8
[ 28.020071] ffffffff829f0b10 0000000000000000 ffffffff81f18460ffff88011a81e340
[ 28.020071] Call Trace:
[ 28.020071] [<ffffffff8106bd88>] process_one_work+0x1c8/0x540
[ 28.020071] [<ffffffff8106bd0b>] ? process_one_work+0x14b/0x540
[ 28.020071] [<ffffffff8106c214>] worker_thread+0x114/0x460
[ 28.020071] [<ffffffff8106c100>] ? process_one_work+0x540/0x540
[ 28.020071] [<ffffffff81071bf8>] kthread+0xf8/0x110
[ 28.020071] [<ffffffff81071b00>] ?kthread_create_on_node+0x200/0x200
[ 28.020071] [<ffffffff81a6522f>] ret_from_fork+0x3f/0x70
[ 28.020071] [<ffffffff81071b00>] ?kthread_create_on_node+0x200/0x200
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v2.6.31+
Pull RCU fixes from Ingo Molnar:
"Two RCU fixes:
- work around bug with recent GCC versions.
- fix false positive lockdep splat"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rcu: Suppress lockdep false positive for rcp->exp_funnel_mutex
rcu: Change _wait_rcu_gp() to work around GCC bug 67055
Some drivers might use the per-cpu interrupts and still might be built as a
module. Export request_percpu_irq an free_percpu_irq to these user, which
also make it consistent with enable/disable_percpu_irq that were exported.
Reported-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The documentation of request_percpu_irq is confusing and suggest that the
interrupt is not enabled at all, while it is actually enabled on the local
CPU.
Clarify that.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull RCU fixes from Paul E. McKenney, for two regressions
introduced in this merge window:
- Fix bug with recent GCCs.
- Fix false positive lockdep splat.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull perf fixes from Thomas Gleixner:
"Another pile of fixes for perf:
- Plug overflows and races in the core code
- Sanitize the flow of the perf syscall so we error out before
handling the more complex and hard to undo setups
- Improve and fix Broadwell and Skylake hardware support
- Revert a fix which broke what it tried to fix in perf tools
- A couple of smaller fixes in various places of perf tools"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools: Fix copying of /proc/kcore
perf intel-pt: Remove no_force_psb from documentation
perf probe: Use existing routine to look for a kernel module by dso->short_name
perf/x86: Change test_aperfmperf() and test_intel() to static
tools lib traceevent: Fix string handling in heterogeneous arch environments
perf record: Avoid infinite loop at buildid processing with no samples
perf: Fix races in computing the header sizes
perf: Fix u16 overflows
perf: Restructure perf syscall point of no return
perf/x86/intel: Fix Skylake FRONTEND MSR extrareg mask
perf/x86/intel/pebs: Add PEBS frontend profiling for Skylake
perf/x86/intel: Make the CYCLE_ACTIVITY.* constraint on Broadwell more specific
perf tools: Bool functions shouldn't return -1
tools build: Add test for presence of __get_cpuid() gcc builtin
tools build: Add test for presence of numa_num_possible_cpus() in libnuma
Revert "perf symbols: Fix mismatched declarations for elf_getphdrnum"
perf stat: Fix per-pkg event reporting bug
Pull scheduler fix from Thomas Gleixner:
"A single bug fix for the scheduler to prevent dequeueing of the idle
task when setting the cpus allowed mask"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Fix crash trying to dequeue/enqueue the idle thread
Pull locking fix from Thomas Gleixner:
"A single bugfix for lockdep to preserve the pinning counter when
rebuilding the lock stack"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/lockdep: Fix hlock->pin_count reset on lock stack rebuilds
The 'sched_domain_topology' variable is only used within kernel/sched/core.c.
Make it static.
Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1442918939-9907-1-git-send-email-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The return value of (do_)balance_runtime() is not consumed by anybody.
Make them return void.
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441188096-23021-5-git-send-email-juri.lelli@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
rt_mutex_waiter_less() check of task deadlines is open coded. Since this
is subject to wraparound bugs, make it use the correct helper.
Reported-by: Luca Abeni <luca.abeni@unitn.it>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441188096-23021-4-git-send-email-juri.lelli@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Move dl_time_before() static definition in include/linux/sched/deadline.h
so that it can be used by different parties without being re-defined.
Reported-by: Luca Abeni <luca.abeni@unitn.it>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441188096-23021-3-git-send-email-juri.lelli@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Various people reported hitting the "unpinning an unpinned lock"
warning. As it turns out there are 2 places where we take a lock out
of the middle of a stack, and in those cases it would fail to preserve
the pin_count when rebuilding the lock stack.
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Reported-by: Tim Spriggs <tspriggs@apple.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davej@codemonkey.org.uk
Link: http://lkml.kernel.org/r/20150916141040.GA11639@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This reverts commit 51360155ec and adapts
fs/userfaultfd.c to use the old version of that function.
It didn't look robust to call __wake_up_common with "nr == 1" when we
absolutely require wakeall semantics, but we've full control of what we
insert in the two waitqueue heads of the blocked userfaults. No
exclusive waitqueue risks to be inserted into those two waitqueue heads
so we can as well stick to "nr == 1" of the old code and we can rely
purely on the fact no waitqueue inserted in one of the two waitqueue
heads we must enforce as wakeall, has wait->flags WQ_FLAG_EXCLUSIVE set.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thierry Reding <treding@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
futex_hash() references two global variables: the base pointer
futex_queues and the size of the array futex_hashsize. The latter is
marked __read_mostly, while the former is not, so they are likely to
end up very far from each other. This means that futex_hash() is
likely to encounter two cache misses.
We could mark futex_queues as __read_mostly as well, but that doesn't
guarantee they'll end up next to each other (and even if they do, they
may still end up in different cache lines). So put the two variables
in a small singleton struct with sufficient alignment and mark that as
__read_mostly.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: kbuild test robot <fengguang.wu@intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/1441834601-13633-1-git-send-email-linux@rasmusvillemoes.dk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
timer_stats_account_timer() reads timer->start_site, then checks it
for NULL and then re-reads it again, while
timer_stats_timer_clear_start_info() can concurrently reset
timer->start_site to NULL. This should not lead to crashes, but can
double number of entries in timer stats as start_site is used during
comparison, the doubled entries will have unuseful NULL start_site.
Read timer->start_site only once in timer_stats_account_timer().
The data race was found with KernelThreadSanitizer (KTSAN).
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: andreyknvl@google.com
Cc: glider@google.com
Cc: kcc@google.com
Cc: ktsan@googlegroups.com
Cc: john.stultz@linaro.org
Link: http://lkml.kernel.org/r/1442584463-69553-1-git-send-email-dvyukov@google.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tianhong Ding <dingtianhong@huawei.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Xinwei Hu <huxinwei@huawei.com>
Cc: Xunlei Pang <pang.xunlei@linaro.org>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/1440484973-13892-1-git-send-email-thunder.leizhen@huawei.com
[ Fixed yet another typo in one of the sentences fixed. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Force threading of interrupts does not really deal with interrupts
which are requested with a primary and a threaded handler. The current
policy is to leave them alone and let the primary handler run in
interrupt context, but we set the ONESHOT flag for those interrupts as
well.
Kohji Okuno debugged a problem with the SDHCI driver where the
interrupt thread waits for a hardware interrupt to trigger, which can't
work well because the hardware interrupt is masked due to the ONESHOT
flag being set. He proposed to set the ONESHOT flag only if the
interrupt does not provide a thread handler.
Though that does not work either because these interrupts can be
shared. So the other interrupt would rightfully get the ONESHOT flag
set and therefor the same situation would happen again.
To deal with this proper, we need to force thread the primary handler
of such interrupts as well. That means that the primary interrupt
handler is treated as any other primary interrupt handler which is not
marked IRQF_NO_THREAD. The threaded handler becomes a separate thread
so the SDHCI flow logic can be handled gracefully.
The same issue was reported against 4.1-rt.
Reported-and-tested-by: Kohji Okuno <okuno.kohji@jp.panasonic.com>
Reported-By: Michal Smucr <msmucr@gmail.com>
Reported-and-tested-by: Nathan Sullivan <nathan.sullivan@ni.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1509211058080.5606@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull cgroup fixes from Tejun Heo:
"The threadgroup locking changes which went in during 4.2 devel cycle
added write locking of a percpu_rwsem in cgroup task migration path;
unfortunately, that involved expedited rcu syncing which turned out to
be too slow and heavy for certain workloads. The patchset which is
dependent on this one didn't get committed during that devel cycle, so
these two patches can be reverted safely.
Oleg reworked percpu_rwsem for 4.4 so that the writer path is a lot
lighter. The reported issue goes away with Oleg's reworked
percpu_rwsem and I'll reapply these patches on the for-4.4 branch so
that they can land together with Oleg's changes"
* 'for-4.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
Revert "sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem"
Revert "cgroup: simplify threadgroup locking"
This commit converts the rcu_data structure's ->cpu_no_qs field
to a union. The bytewise side of this union allows individual access
to indications as to whether this CPU needs to find a quiescent state
for a normal (.norm) and/or expedited (.exp) grace period. The setwise
side of the union allows testing whether or not a quiescent state is
needed at all, for either type of grace period.
For now, only .norm is used. A later commit will introduce the expedited
usage.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit inverts the sense of the rcu_data structure's ->passed_quiesce
field and renames it to ->cpu_no_qs. This will allow a later commit to
use an "aggregate OR" operation to test expedited as well as normal grace
periods without added overhead.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
An upcoming commit needs to invert the sense of the ->passed_quiesce
rcu_data structure field, so this commit is taking this opportunity
to clarify things a bit by renaming ->qs_pending to ->core_needs_qs.
So if !rdp->core_needs_qs, then this CPU need not concern itself with
quiescent states, in particular, it need not acquire its leaf rcu_node
structure's ->lock to check. Otherwise, it needs to report the next
quiescent state.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Currently, synchronize_sched_expedited() uses a single global counter
to track the number of remaining context switches that the current
expedited grace period must wait on. This is problematic on large
systems, where the resulting memory contention can be pathological.
This commit therefore makes synchronize_sched_expedited() instead use
the combining tree in the same manner as synchronize_rcu_expedited(),
keeping memory contention down to a dull roar.
This commit creates a temporary function sync_sched_exp_select_cpus()
that is very similar to sync_rcu_exp_select_cpus(). A later commit
will consolidate these two functions, which becomes possible when
synchronize_sched_expedited() switches from stop_one_cpu_nowait() to
smp_call_function_single().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The current preemptible-RCU expedited grace-period algorithm invokes
synchronize_sched_expedited() to enqueue all tasks currently running
in a preemptible-RCU read-side critical section, then waits for all the
->blkd_tasks lists to drain. This works, but results in both an IPI and
a double context switch even on CPUs that do not happen to be running
in a preemptible RCU read-side critical section.
This commit implements a new algorithm that causes less OS jitter.
This new algorithm IPIs all online CPUs that are not idle (from an
RCU perspective), but refrains from self-IPIs. If a CPU receiving
this IPI is not in a preemptible RCU read-side critical section (or
is just now exiting one), it pushes quiescence up the rcu_node tree,
otherwise, it sets a flag that will be handled by the upcoming outermost
rcu_read_unlock(), which will then push quiescence up the tree.
The expedited grace period must of course wait on any pre-existing blocked
readers, and newly blocked readers must be queued carefully based on
the state of both the normal and the expedited grace periods. This
new queueing approach also avoids the need to update boost state,
courtesy of the fact that blocked tasks are no longer ever migrated to
the root rcu_node structure.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit replaces sync_rcu_preempt_exp_init1(() and
sync_rcu_preempt_exp_init2() with sync_exp_reset_tree_hotplug()
and sync_exp_reset_tree(), which will also be used by
synchronize_sched_expedited(), and sync_rcu_exp_select_nodes(), which
contains code specific to synchronize_rcu_expedited().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This is a nearly pure code-movement commit, moving rcu_report_exp_rnp(),
sync_rcu_preempt_exp_done(), and rcu_preempted_readers_exp() so
that later commits can make synchronize_sched_expedited() use them.
The non-code-movement portion of this commit tags rcu_report_exp_rnp()
as __maybe_unused to avoid build errors when CONFIG_PREEMPT=n.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Now that there is an ->expedited_wq waitqueue in each rcu_state structure,
there is no need for the sync_rcu_preempt_exp_wq global variable. This
commit therefore substitutes ->expedited_wq for sync_rcu_preempt_exp_wq.
It also initializes ->expedited_wq only once at boot instead of at the
start of each expedited grace period.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
In kernels built with CONFIG_PREEMPT=y, synchronize_rcu_expedited()
invokes synchronize_sched_expedited() while holding RCU-preempt's
root rcu_node structure's ->exp_funnel_mutex, which is acquired after
the rcu_data structure's ->exp_funnel_mutex. The first thing that
synchronize_sched_expedited() will do is acquire RCU-sched's rcu_data
structure's ->exp_funnel_mutex. There is no danger of an actual deadlock
because the locking order is always from RCU-preempt's expedited mutexes
to those of RCU-sched. Unfortunately, lockdep considers both rcu_data
structures' ->exp_funnel_mutex to be in the same lock class and therefore
reports a deadlock cycle.
This commit silences this false positive by placing RCU-sched's rcu_data
structures' ->exp_funnel_mutex locks into their own lock class.
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"Mostly stable material, a lot of ARM fixes"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits)
sched: access local runqueue directly in single_task_running
arm/arm64: KVM: Remove 'config KVM_ARM_MAX_VCPUS'
arm64: KVM: Remove all traces of the ThumbEE registers
arm: KVM: Disable virtual timer even if the guest is not using it
arm64: KVM: Disable virtual timer even if the guest is not using it
arm/arm64: KVM: vgic: Check for !irqchip_in_kernel() when mapping resources
KVM: s390: Replace incorrect atomic_or with atomic_andnot
arm: KVM: Fix incorrect device to IPA mapping
arm64: KVM: Fix user access for debug registers
KVM: vmx: fix VPID is 0000H in non-root operation
KVM: add halt_attempted_poll to VCPU stats
kvm: fix zero length mmio searching
kvm: fix double free for fast mmio eventfd
kvm: factor out core eventfd assign/deassign logic
kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd
KVM: make the declaration of functions within 80 characters
KVM: arm64: add workaround for Cortex-A57 erratum #852523
KVM: fix polling for guest halt continued even if disable it
arm/arm64: KVM: Fix PSCI affinity info return value for non valid cores
arm64: KVM: set {v,}TCR_EL2 RES1 bits
...
Pull irq updates from Thomas Gleixner:
"This is a rather large update post rc1 due to the final steps of
cleanups and API changes which had to wait for the preparatory patches
to hit your tree.
- Regression fixes for ARM GIC irqchips
- Regression fixes and lockdep anotations for renesas irq chips
- The leftovers of the cleanup and preparatory patches which have
been ignored by maintainers
- Final conversions of the newly merged users of obsolete APIs
- Final removal of obsolete APIs
- Final removal of ARM artifacts which had been introduced during the
conversion of ARM to the generic interrupt code.
- Final split of the irq_data into chip specific and common data to
reflect the needs of hierarchical irq domains.
- Treewide removal of the first argument of interrupt flow handlers,
i.e. the irq number, which is not used by the majority of handlers
and simple to retrieve from the other argument the irq descriptor.
- A few comment updates and build warning fixes"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
arm64: Remove ununsed set_irq_flags
ARM: Remove ununsed set_irq_flags
sh: Kill off set_irq_flags usage
irqchip: Kill off set_irq_flags usage
gpu/drm: Kill off set_irq_flags usage
genirq: Remove irq argument from irq flow handlers
genirq: Move field 'msi_desc' from irq_data into irq_common_data
genirq: Move field 'affinity' from irq_data into irq_common_data
genirq: Move field 'handler_data' from irq_data into irq_common_data
genirq: Move field 'node' from irq_data into irq_common_data
irqchip/gic-v3: Use IRQD_FORWARDED_TO_VCPU flag
irqchip/gic: Use IRQD_FORWARDED_TO_VCPU flag
genirq: Provide IRQD_FORWARDED_TO_VCPU status flag
genirq: Simplify irq_data_to_desc()
genirq: Remove __irq_set_handler_locked()
pinctrl/pistachio: Use irq_set_handler_locked
gpio: vf610: Use irq_set_handler_locked
powerpc/mpc8xx: Use irq_set_handler_locked()
powerpc/ipic: Use irq_set_handler_locked()
powerpc/cpm2: Use irq_set_handler_locked()
...
Commit 2ee507c472 ("sched: Add function single_task_running to let a task
check if it is the only task running on a cpu") referenced the current
runqueue with the smp_processor_id. When CONFIG_DEBUG_PREEMPT is enabled,
that is only allowed if preemption is disabled or the currrent task is
bound to the local cpu (e.g. kernel worker).
With commit f781951299 ("kvm: add halt_poll_ns module parameter") KVM
calls single_task_running. If CONFIG_DEBUG_PREEMPT is enabled that
generates a lot of kernel messages.
To avoid adding preemption in that cases, as it would limit the usefulness,
we change single_task_running to access directly the cpu local runqueue.
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Fixes: 2ee507c472
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If _Q_SLOW_VAL has been set, the vCPU state must have been vcpu_hashed.
The extra check at the end of __pv_queued_spin_unlock() is unnecessary
and can be removed.
Signed-off-by: Waiman Long <Waiman.Long@hpe.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1441996658-62854-3-git-send-email-Waiman.Long@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
... by using acquire/release for ops around the lock->tail. As such,
weakly ordered archs can benefit from more relaxed use of barriers
when issuing atomics.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hpe.com>
Link: http://lkml.kernel.org/r/1442216244-4409-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
... trivial, but reads a little nicer when we name our
actual primitive 'lock'.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hpe.com>
Link: http://lkml.kernel.org/r/1442216244-4409-1-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The group_classify() function does not use the "env" parameter, so remove it.
Also unify code to always use group_classify() to calculate group's
load type.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1442314605-14838-1-git-send-email-leo.yan@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Macro LOAD_AVG_MAX is defined far away from the precompuated tables
for decay calculation in code; So explicitly comments for this.
Also fix one typo: s/LOAD_MAX_AVG/LOAD_AVG_MAX.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1442314657-14949-1-git-send-email-leo.yan@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently task_numa_work() scans up to numa_balancing_scan_size_mb worth
of memory per invocation, but only counts memory areas that have at
least one PTE that is still present and not marked for numa hint faulting.
It will skip over arbitarily large amounts of memory that are either
unused, full of swap ptes, or full of PTEs that were already marked
for NUMA hint faults but have not been faulted on yet.
This can cause excessive amounts of CPU use, due to there being
essentially no upper limit on the scan rate of very large processes
that are not yet in a phase where they are actively accessing old
memory pages (eg. they are still initializing their data).
Avoid that problem by placing an upper limit on the amount of virtual
memory that task_numa_work() scans in each invocation. This can be a
higher limit than "pages", to ensure the task still skips over unused
areas fairly quickly.
While we are here, also fix the "nr_pte_updates" logic, so it only
counts page ranges with ptes in them.
Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150911090027.4a7987bd@annuminas.surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Most of the policy-tests are done via the <class>_policy() helpers with
the notable exception of idle. A new wrapper for valid_policy() has also
been added to improve readability in set_load_weight().
This commit does not change the logical behavior of the scheduler core.
Signed-off-by: Henrik Austad <henrik@austad.us>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1441810841-4756-1-git-send-email-henrik@austad.us
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There are two races with the current code:
- Another event can join the group and compute a larger header_size
concurrently, if the smaller store wins we'll have an incorrect
header_size set.
- We compute the header_size after the event becomes active,
therefore its possible to use the size before its computed.
Remedy the first by moving the computation inside the ctx::mutex lock,
and the second by placing it _before_ perf_install_in_context().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
