Messages in this thread | | | Date | Mon, 18 May 2015 16:41:37 +0200 | From | Michal Hocko <> | Subject | Re: suspend regression in 4.1-rc1 |
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On Mon 18-05-15 10:26:07, Don Zickus wrote: > On Mon, May 18, 2015 at 06:56:46AM -0400, Ulrich Obergfell wrote: > > > > > There further appears to be a distinct lack of serialization between > > > setting and using watchdog_enabled, so perhaps we should wrap the > > > {en,dis}able_all() things in watchdog_proc_mutex. > > > > As I understand it, the {en,dis}able_all() functions are only called early > > at kernel startup, so I do not see how they could be racing with watchdog > > code that is executed in the context of write() system calls to parameters > > in /proc/sys/kernel. Please see also my earlier reply to Michal for further > > details: http://marc.info/?l=linux-pm&m=143194387208250&w=2 > > > > Do we really need synchronization here? > > As Peter said we have to focus on doing things correctly and not based on > what is currently. > > During s2ram, I believe all the threads get parked and then unparked during > resume. I am wondering if the race happens there, threads get unparked and > stomp on each other when watchdog_nmi_enable_all() is called.
Wouldn't that cause an issue during freezer mode of pm_test? I can see it much later in the processors mode. -- Michal Hocko SUSE Labs
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