Frederic Weisbecker
7bdb59f1ad
tick/nohz: Fix possible missing clock reprog after tick soft restart
...
ts->next_tick keeps track of the next tick deadline in order to optimize
clock programmation on irq exit and avoid redundant clock device writes.
Now if ts->next_tick missed an update, we may spuriously miss a clock
reprog later as the nohz code is fooled by an obsolete next_tick value.
This is what happens here on a specific path: when we observe an
expired timer from the nohz update code on irq exit, we perform a soft
tick restart which simply fires the closest possible tick without
actually exiting the nohz mode and restoring a periodic state. But we
forget to update ts->next_tick accordingly.
As a result, after the next tick resulting from such soft tick restart,
the nohz code sees a stale value on ts->next_tick which doesn't match
the clock deadline that just expired. If that obsolete ts->next_tick
value happens to collide with the actual next tick deadline to be
scheduled, we may spuriously bypass the clock reprogramming. In the
worst case, the tick may never fire again.
Fix this with a ts->next_tick reset on soft tick restart.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed: Wanpeng Li <wanpeng.li@hotmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1486485894-29173-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-10 09:43:48 +01:00
..
bpf
bpf: don't trigger OOM killer under pressure with map alloc
2017-01-18 17:12:26 -05:00
configs
debug
kdb: call vkdb_printf() from vprintk_default() only when wanted
2016-12-14 16:04:08 -08:00
events
perf/core: Fix PERF_RECORD_MMAP2 prot/flags for anonymous memory
2017-01-30 11:41:26 +01:00
gcov
irq
irqdomain: Avoid activating interrupts more than once
2017-01-30 15:18:56 +01:00
livepatch
locking
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
power
Merge branches 'pm-sleep' and 'pm-cpufreq'
2017-01-27 00:08:59 +01:00
printk
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
rcu
rcu: Narrow early boot window of illegal synchronous grace periods
2017-01-14 21:23:48 -08:00
sched
ktime: Cleanup ktime_set() usage
2016-12-25 17:21:22 +01:00
time
tick/nohz: Fix possible missing clock reprog after tick soft restart
2017-02-10 09:43:48 +01:00
trace
tracing/kprobes: Fix __init annotation
2017-02-02 10:48:35 -05:00
.gitignore
acct.c
async.c
audit.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2016-12-17 18:44:00 -08:00
audit.h
audit_log_{name,link_denied}: constify struct path
2016-12-05 19:00:38 -05:00
audit_fsnotify.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2016-12-17 18:44:00 -08:00
audit_tree.c
Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit
2017-01-05 23:06:06 -08:00
audit_watch.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2016-12-17 18:44:00 -08:00
auditfilter.c
audit: add support for session ID user filter
2016-11-29 15:10:12 -05:00
auditsc.c
Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit
2016-12-14 14:06:40 -08:00
backtracetest.c
bounds.c
capability.c
capability: export has_capability
2017-01-12 07:01:56 -07:00
cgroup.c
cgroup: don't online subsystems before cgroup_name/path() are operational
2017-01-26 16:47:28 -05:00
cgroup_freezer.c
cgroup_pids.c
compat.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
configs.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
context_tracking.c
cpu.c
cpu/hotplug: Remove unused but set variable in _cpu_down()
2017-01-18 11:55:09 +01:00
cpu_pm.c
cpuset.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
extable.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
fork.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
freezer.c
futex.c
ktime: Get rid of the union
2016-12-25 17:21:22 +01:00
futex_compat.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
groups.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
hung_task.c
hung_task: decrement sysctl_hung_task_warnings only if it is positive
2016-12-12 18:55:09 -08:00
irq_work.c
jump_label.c
jump_labels: API for flushing deferred jump label updates
2017-01-12 14:33:16 +01:00
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
locking/mutex: Allow MUTEX_SPIN_ON_OWNER when DEBUG_MUTEXES
2016-10-25 11:31:51 +02:00
Kconfig.preempt
kcov.c
kcov: make kcov work properly with KASLR enabled
2016-12-20 09:48:47 -08:00
kexec.c
kexec_core.c
kexec: add cond_resched into kimage_alloc_crash_control_pages
2016-12-14 16:04:07 -08:00
kexec_file.c
ima: on soft reboot, save the measurement list
2016-12-20 09:48:44 -08:00
kexec_internal.h
kexec_file: Allow arch-specific memory walking for kexec_add_buffer
2016-11-30 23:14:57 +11:00
kmod.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
kprobes.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
ksysfs.c
kthread.c
kthread: add __printf attributes
2016-12-12 18:55:06 -08:00
latencytop.c
Makefile
Merge branch 'akpm' (patches from Andrew)
2016-12-14 17:25:18 -08:00
membarrier.c
memremap.c
mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done}
2017-01-10 18:31:54 -08:00
module-internal.h
module.c
modversions: treat symbol CRCs as 32 bit quantities
2017-02-03 08:28:25 -08:00
module_signing.c
notifier.c
nsproxy.c
padata.c
padata: Remove unused but set variables
2016-10-25 11:08:10 +08:00
panic.c
kernel/panic.c: add missing \n
2017-01-24 16:26:14 -08:00
params.c
pid.c
pid_namespace.c
pid: fix lockdep deadlock warning due to ucount_lock
2017-01-10 13:34:56 +13:00
profile.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
ptrace.c
ptrace: Don't allow accessing an undumpable mm
2016-11-22 12:57:38 -06:00
range.c
reboot.c
relay.c
relay: check array offset before using it
2016-12-14 16:04:08 -08:00
resource.c
seccomp.c
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2016-12-14 13:57:44 -08:00
signal.c
signal: protect SIGNAL_UNKILLABLE from unintentional clearing.
2017-01-10 18:31:55 -08:00
smp.c
kernel/smp: Tell the user we're bringing up secondary CPUs
2016-10-26 12:02:35 +02:00
smpboot.c
smpboot.h
softirq.c
softirq: Display IRQ_POLL for irq-poll statistics
2016-10-21 15:45:47 -06:00
stacktrace.c
stop_machine.c
locking/core, stop_machine: Yield the CPU during stop machine()
2016-11-16 10:15:09 +01:00
sys.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
sys_ni.c
move aio compat to fs/aio.c
2016-12-22 22:58:37 -05:00
sysctl.c
sysctl: fix proc_doulongvec_ms_jiffies_minmax()
2017-01-26 09:21:24 -08:00
sysctl_binary.c
sysctl: add KERN_CONT to deprecated_sysctl_warning()
2016-12-14 16:04:07 -08:00
task_work.c
taskstats.c
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
2016-11-15 10:54:36 -05:00
test_kprobes.c
torture.c
tracepoint.c
tracing: Have the reg function allow to fail
2016-12-09 09:13:30 -05:00
tsacct.c
ucount.c
kernel/ucount.c: mark user_header with kmemleak_ignore()
2017-02-08 15:41:43 -08:00
uid16.c
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
2016-12-24 11:46:01 -08:00
up.c
user-return-notifier.c
user.c
user_namespace.c
utsname.c
utsname_sysctl.c
watchdog.c
kernel/watchdog: prevent false hardlockup on overloaded system
2017-01-24 16:26:14 -08:00
watchdog_hld.c
kernel/watchdog: prevent false hardlockup on overloaded system
2017-01-24 16:26:14 -08:00
workqueue.c
Merge branch 'for-4.9' into for-4.10
2016-10-19 12:12:40 -04:00
workqueue_internal.h