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| author |   Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2019-03-07 16:26:50 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-07 18:31:59 -0800 |
| commit | b014bebab047e9fdf2df45f6504ccbeaca446321 (patch) | |
| tree | 20945c60d22ed75e987aa032264a59a54468b426 /kernel | |
| parent | kernel/hung_task.c - fix sparse warnings (diff) | |
| download | linux-dev-b014bebab047e9fdf2df45f6504ccbeaca446321.tar.xz linux-dev-b014bebab047e9fdf2df45f6504ccbeaca446321.zip | |
kernel/hung_task.c: Use continuously blocked time when reporting.
Since commit a2e514453861 ("kernel/hung_task.c: allow to set checking
interval separately from timeout") added hung_task_check_interval_secs,
setting a value different from hung_task_timeout_secs
echo 0 > /proc/sys/kernel/hung_task_panic
echo 120 > /proc/sys/kernel/hung_task_timeout_secs
echo 5 > /proc/sys/kernel/hung_task_check_interval_secs
causes confusing output as if the task was blocked for
hung_task_timeout_secs seconds from the previous report.
[ 399.395930] INFO: task kswapd0:75 blocked for more than 120 seconds.
[ 405.027637] INFO: task kswapd0:75 blocked for more than 120 seconds.
[ 410.659725] INFO: task kswapd0:75 blocked for more than 120 seconds.
[ 416.292860] INFO: task kswapd0:75 blocked for more than 120 seconds.
[ 421.932305] INFO: task kswapd0:75 blocked for more than 120 seconds.
Although we could update t->last_switch_time after sched_show_task(t) if
we want to report only every 120 seconds, reporting every 5 seconds
might not be very bad for monitoring after a problematic situation has
started. Thus, let's use continuously blocked time instead of updating
previously reported time.
[ 677.985011] INFO: task kswapd0:80 blocked for more than 122 seconds.
[ 693.856126] INFO: task kswapd0:80 blocked for more than 138 seconds.
[ 709.728075] INFO: task kswapd0:80 blocked for more than 154 seconds.
[ 725.600018] INFO: task kswapd0:80 blocked for more than 170 seconds.
[ 741.473133] INFO: task kswapd0:80 blocked for more than 186 seconds.
Link: http://lkml.kernel.org/r/1551175083-10669-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/hung_task.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 0c11216171c9..f108a95882c6 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -127,7 +127,7 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout) if (sysctl_hung_task_warnings > 0) sysctl_hung_task_warnings--; pr_err("INFO: task %s:%d blocked for more than %ld seconds.\n", - t->comm, t->pid, timeout); + t->comm, t->pid, (jiffies - t->last_switch_time) / HZ); pr_err(" %s %s %.*s\n", print_tainted(), init_utsname()->release, (int)strcspn(init_utsname()->version, " "), |