From: Wei Li Date: Thu, 26 Dec 2019 08:52:24 +0000 (+0800) Subject: sched/debug: Reset watchdog on all CPUs while processing sysrq-t X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=02d4ac5885a18d326b500b94808f0956dcce2832;p=linux.git sched/debug: Reset watchdog on all CPUs while processing sysrq-t Lengthy output of sysrq-t may take a lot of time on slow serial console with lots of processes and CPUs. So we need to reset NMI-watchdog to avoid spurious lockup messages, and we also reset softlockup watchdogs on all other CPUs since another CPU might be blocked waiting for us to process an IPI or stop_machine. Add to sysrq_sched_debug_show() as what we did in show_state_filter(). Signed-off-by: Wei Li Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Steven Rostedt (VMware) Link: https://lkml.kernel.org/r/20191226085224.48942-1-liwei391@huawei.com --- diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index f7e4579e746c5..879d3ccf38064 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -751,9 +751,16 @@ void sysrq_sched_debug_show(void) int cpu; sched_debug_header(NULL); - for_each_online_cpu(cpu) + for_each_online_cpu(cpu) { + /* + * Need to reset softlockup watchdogs on all CPUs, because + * another CPU might be blocked waiting for us to process + * an IPI or stop_machine. + */ + touch_nmi_watchdog(); + touch_all_softlockup_watchdogs(); print_cpu(NULL, cpu); - + } } /*