Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Frederic Weisbecker 24b91e360e nohz: Fix collision between tick and other hrtimers ... When the tick is stopped and an interrupt occurs afterward, we check on that interrupt exit if the next tick needs to be rescheduled. If it doesn't need any update, we don't want to do anything. In order to check if the tick needs an update, we compare it against the clockevent device deadline. Now that's a problem because the clockevent device is at a lower level than the tick itself if it is implemented on top of hrtimer. Every hrtimer share this clockevent device. So comparing the next tick deadline against the clockevent device deadline is wrong because the device may be programmed for another hrtimer whose deadline collides with the tick. As a result we may end up not reprogramming the tick accidentally. In a worst case scenario under full dynticks mode, the tick stops firing as it is supposed to every 1hz, leaving /proc/stat stalled: Task in a full dynticks CPU ---------------------------- * hrtimer A is queued 2 seconds ahead * the tick is stopped, scheduled 1 second ahead * tick fires 1 second later * on tick exit, nohz schedules the tick 1 second ahead but sees the clockevent device is already programmed to that deadline, fooled by hrtimer A, the tick isn't rescheduled. * hrtimer A is cancelled before its deadline * tick never fires again until an interrupt happens... In order to fix this, store the next tick deadline to the tick_sched local structure and reuse that value later to check whether we need to reprogram the clock after an interrupt. On the other hand, ts->sleep_length still wants to know about the next clock event and not just the tick, so we want to improve the related comment to avoid confusion. Reported-by: James Hartsock <hartsjc@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Rik van Riel <riel@redhat.com> Link: http://lkml.kernel.org/r/1483539124-5693-1-git-send-email-fweisbec@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>		2017-01-11 10:41:33 +01:00
..
bpf	bpf: fix mark_reg_unknown_value for spilled regs on map value marking	2016-12-17 21:27:44 -05:00
configs	config: android: enable CONFIG_SECCOMP	2016-10-11 15:06:32 -07:00
debug	kdb: call vkdb_printf() from vprintk_default() only when wanted	2016-12-14 16:04:08 -08:00
events	Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-12-23 16:49:12 -08:00
gcov
irq	genirq/affinity: Fix node generation from cpumask	2016-12-15 12:32:35 +01:00
livepatch
locking	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
power	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
printk	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
rcu	rcu: Don't kick unless grace period or request	2016-11-14 10:46:31 -08:00
sched	ktime: Cleanup ktime_set() usage	2016-12-25 17:21:22 +01:00
time	nohz: Fix collision between tick and other hrtimers	2017-01-11 10:41:33 +01:00
trace	clocksource: Use a plain u64 instead of cycle_t	2016-12-25 11:04:12 +01:00
.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	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -08:00
cgroup.c	cgroup: add support for eBPF programs	2016-11-25 16:25:52 -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	smp/hotplug: Undo tglxs brainfart	2016-12-26 17:30:24 -08:00
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
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
module-internal.h
module.c	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -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	taint/module: Clean up global and module taint flags handling	2016-11-26 11:18:01 -08:00
params.c
pid.c
pid_namespace.c
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	ktime: Get rid of the union	2016-12-25 17:21:22 +01:00
smp.c	kernel/smp: Tell the user we're bringing up secondary CPUs	2016-10-26 12:02:35 +02:00
smpboot.c	kthread/smpboot: do not park in kthread_create_on_cpu()	2016-10-11 15:06:33 -07:00
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	Replace <asm/uaccess.h> with <linux/uaccess.h> globally	2016-12-24 11:46:01 -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
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.c: move hardlockup detector to separate file	2016-12-14 16:04:08 -08:00
watchdog_hld.c	kernel/watchdog.c: move hardlockup detector to separate file	2016-12-14 16:04:08 -08:00
workqueue.c	Merge branch 'for-4.9' into for-4.10	2016-10-19 12:12:40 -04:00
workqueue_internal.h