Re: [PATCH][RFC v2] PM / Hibernate: Disable wathdog when creating snapshot

From: Chen Yu
Date: Wed Aug 16 2017 - 10:31:25 EST


On Wed, Aug 16, 2017 at 02:33:59PM +0200, Michal Hocko wrote:
> On Wed 16-08-17 12:53:38, Chen Yu wrote:
> [...]
> > @@ -2537,10 +2538,15 @@ void mark_free_pages(struct zone *zone)
> > unsigned long flags;
> > unsigned int order, t;
> > struct page *page;
> > + bool wd_suspended;
> >
> > if (zone_is_empty(zone))
> > return;
> >
> > + wd_suspended = lockup_detector_suspend() ? false : true;
> > + if (!wd_suspended)
> > + pr_warn_once("Failed to disable lockup detector during hibernation.\n");
> > +
> > spin_lock_irqsave(&zone->lock, flags);
> >
> > max_zone_pfn = zone_end_pfn(zone);
>
> I am not maintainer of this code so I am not very familiar with the full
> context of this function but lockup_detector_suspend is just too heavy
> for the purpose you are trying to achive. Really why don't you just
> poke the watchdog every N pages?
OK, I'll send another version.
Thanks,
Yu
> --
> Michal Hocko
> SUSE Labs