Messages in this thread |  | | Date | Tue, 7 Jan 2020 10:32:14 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] sched/debug: Reset watchdog on all CPUs while processing sysrq-t |
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On Thu, Jan 02, 2020 at 02:45:14PM -0500, Steven Rostedt wrote: > On Thu, 26 Dec 2019 16:52:24 +0800 > Wei Li <liwei391@huawei.com> wrote: > > > 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. > > Have you had this triggered? > > > > > Add to sysrq_sched_debug_show() as what we did in show_state_filter(). > > > > Signed-off-by: Wei Li <liwei391@huawei.com> > > --- > > kernel/sched/debug.c | 11 +++++++++-- > > 1 file changed, 9 insertions(+), 2 deletions(-) > > > > diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c > > index f7e4579e746c..879d3ccf3806 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(); > > This doesn't seem to hurt to add, thus. > > Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Thanks!
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