Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue update from Tejun Heo:
 "Workqueue changes for v4.5.  One cleanup patch and three to improve
  the debuggability.

  Workqueue now has a stall detector which dumps workqueue state if any
  worker pool hasn't made forward progress over a certain amount of time
  (30s by default) and also triggers a warning if a workqueue which can
  be used in memory reclaim path tries to wait on something which can't
  be.

  These should make workqueue hangs a lot easier to debug."

* 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: simplify the apply_workqueue_attrs_locked()
  workqueue: implement lockup detector
  watchdog: introduce touch_softlockup_watchdog_sched()
  workqueue: warn if memory reclaim tries to flush !WQ_MEM_RECLAIM workqueue
This commit is contained in:
Linus Torvalds
2016-01-11 18:53:13 -08:00
8 changed files with 261 additions and 15 deletions

View File

@@ -20,6 +20,7 @@
#include <linux/smpboot.h>
#include <linux/sched/rt.h>
#include <linux/tick.h>
#include <linux/workqueue.h>
#include <asm/irq_regs.h>
#include <linux/kvm_para.h>
@@ -225,7 +226,15 @@ static void __touch_watchdog(void)
__this_cpu_write(watchdog_touch_ts, get_timestamp());
}
void touch_softlockup_watchdog(void)
/**
* touch_softlockup_watchdog_sched - touch watchdog on scheduler stalls
*
* Call when the scheduler may have stalled for legitimate reasons
* preventing the watchdog task from executing - e.g. the scheduler
* entering idle state. This should only be used for scheduler events.
* Use touch_softlockup_watchdog() for everything else.
*/
void touch_softlockup_watchdog_sched(void)
{
/*
* Preemption can be enabled. It doesn't matter which CPU's timestamp
@@ -233,6 +242,12 @@ void touch_softlockup_watchdog(void)
*/
raw_cpu_write(watchdog_touch_ts, 0);
}
void touch_softlockup_watchdog(void)
{
touch_softlockup_watchdog_sched();
wq_watchdog_touch(raw_smp_processor_id());
}
EXPORT_SYMBOL(touch_softlockup_watchdog);
void touch_all_softlockup_watchdogs(void)
@@ -246,6 +261,7 @@ void touch_all_softlockup_watchdogs(void)
*/
for_each_watchdog_cpu(cpu)
per_cpu(watchdog_touch_ts, cpu) = 0;
wq_watchdog_touch(-1);
}
#ifdef CONFIG_HARDLOCKUP_DETECTOR