Messages in this thread Patch in this message | | | From | Wang Qing <> | Subject | [PATCH V2] workqueue: watchdog: update wq_watchdog_touched for unbound lockup checking | Date | Fri, 19 Mar 2021 16:00:36 +0800 |
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When touch_softlockup_watchdog() is called, only wq_watchdog_touched_cpu updated, while the unbound worker_pool running on its core uses wq_watchdog_touched to determine whether locked up. This may be mischecked.
My suggestion is to update both when touch_softlockup_watchdog() is called, use wq_watchdog_touched_cpu to check bound, and use wq_watchdog_touched to check unbound worker_pool.
Signed-off-by: Wang Qing <wangqing@vivo.com> --- kernel/watchdog.c | 5 +++-- kernel/workqueue.c | 17 ++++++----------- 2 files changed, 9 insertions(+), 13 deletions(-)
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 7110906..107bc38 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -278,9 +278,10 @@ void touch_all_softlockup_watchdogs(void) * update as well, the only side effect might be a cycle delay for * the softlockup check. */ - for_each_cpu(cpu, &watchdog_allowed_mask) + for_each_cpu(cpu, &watchdog_allowed_mask) { per_cpu(watchdog_touch_ts, cpu) = SOFTLOCKUP_RESET; - wq_watchdog_touch(-1); + wq_watchdog_touch(cpu); + } } void touch_softlockup_watchdog_sync(void) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 0d150da..be08295 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -5787,22 +5787,17 @@ static void wq_watchdog_timer_fn(struct timer_list *unused) continue; /* get the latest of pool and touched timestamps */ + if (pool->cpu >= 0) + touched = READ_ONCE(per_cpu(wq_watchdog_touched_cpu, pool->cpu)); + else + touched = READ_ONCE(wq_watchdog_touched); pool_ts = READ_ONCE(pool->watchdog_ts); - touched = READ_ONCE(wq_watchdog_touched); if (time_after(pool_ts, touched)) ts = pool_ts; else ts = touched; - if (pool->cpu >= 0) { - unsigned long cpu_touched = - READ_ONCE(per_cpu(wq_watchdog_touched_cpu, - pool->cpu)); - if (time_after(cpu_touched, ts)) - ts = cpu_touched; - } - /* did we stall? */ if (time_after(jiffies, ts + thresh)) { lockup_detected = true; @@ -5826,8 +5821,8 @@ notrace void wq_watchdog_touch(int cpu) { if (cpu >= 0) per_cpu(wq_watchdog_touched_cpu, cpu) = jiffies; - else - wq_watchdog_touched = jiffies; + + wq_watchdog_touched = jiffies; } static void wq_watchdog_set_thresh(unsigned long thresh) -- 2.7.4
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