diff options
| author | Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> | 2018-01-11 09:53:35 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-01-23 19:57:08 +0100 |
| commit | ca2d736867200b931ca61383af2fd68bb5fd2ecb (patch) | |
| tree | 6775ae7c626a5a426878b1233e6218eb6a1cce07 /kernel/workqueue.c | |
| parent | d314f3bc7f3d0853e38364c95b1d30fb4e33e989 (diff) | |
workqueue: avoid hard lockups in show_workqueue_state()
commit 62635ea8c18f0f62df4cc58379e4f1d33afd5801 upstream.
show_workqueue_state() can print out a lot of messages while being in
atomic context, e.g. sysrq-t -> show_workqueue_state(). If the console
device is slow it may end up triggering NMI hard lockup watchdog.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/workqueue.c')
| -rw-r--r-- | kernel/workqueue.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 181c2ad0cb54..ebfea5f94b66 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -48,6 +48,7 @@ #include <linux/nodemask.h> #include <linux/moduleparam.h> #include <linux/uaccess.h> +#include <linux/nmi.h> #include "workqueue_internal.h" @@ -4424,6 +4425,12 @@ void show_workqueue_state(void) if (pwq->nr_active || !list_empty(&pwq->delayed_works)) show_pwq(pwq); spin_unlock_irqrestore(&pwq->pool->lock, flags); + /* + * We could be printing a lot from atomic context, e.g. + * sysrq-t -> show_workqueue_state(). Avoid triggering + * hard lockup. + */ + touch_nmi_watchdog(); } } @@ -4451,6 +4458,12 @@ void show_workqueue_state(void) pr_cont("\n"); next_pool: spin_unlock_irqrestore(&pool->lock, flags); + /* + * We could be printing a lot from atomic context, e.g. + * sysrq-t -> show_workqueue_state(). Avoid triggering + * hard lockup. + */ + touch_nmi_watchdog(); } rcu_read_unlock_sched(); |