Re: [PATCH][RFC] PM / Hibernate: Feed NMI wathdog when creating snapshot

From	Chen Yu <yu.c.chen@intel.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH][RFC] PM / Hibernate: Feed NMI wathdog when creating snapshot
Date	2017-08-16 07:00 +0200
Message-ID	<ueYAX-2vJ-41@gated-at.bofh.it> (permalink)
References	<uerbY-6WD-11@gated-at.bofh.it> <ueJse-1mE-15@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Tue, Aug 15, 2017 at 02:41:19PM +0200, Michal Hocko wrote:
> On Tue 15-08-17 01:19:16, Chen Yu wrote:
> [...]
> > @@ -2561,8 +2562,10 @@ void mark_free_pages(struct zone *zone)
> >  			unsigned long i;
> >  
> >  			pfn = page_to_pfn(page);
> > -			for (i = 0; i < (1UL << order); i++)
> > +			for (i = 0; i < (1UL << order); i++) {
> >  				swsusp_set_page_free(pfn_to_page(pfn + i));
> > +				touch_nmi_watchdog();
> > +			}
> 
> this is rather excessive. Why don't you simply call touch_nmi_watchdog
> once per every 1000 pages? Or once per free_list entry?
> 
> Moreover why don't you need to touch_nmi_watchdog in the loop over all
> pfns in the zone (right above this loop)?
> --
After re-checking the code, I think we can simply disable the watchdog
temporarily, thus to avoid feeding the watchdog in the loop.
I'm sending another version based on this.
Thanks,
	Yu
> Michal Hocko
> SUSE Labs

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[PATCH][RFC] PM / Hibernate: Feed NMI wathdog when creating snapshot Chen Yu <yu.c.chen@intel.com> - 2017-08-14 19:20 +0200
  Re: [PATCH][RFC] PM / Hibernate: Feed NMI wathdog when creating  snapshot Michal Hocko <mhocko@kernel.org> - 2017-08-15 14:50 +0200
    Re: [PATCH][RFC] PM / Hibernate: Feed NMI wathdog when creating  snapshot Chen Yu <yu.c.chen@intel.com> - 2017-08-15 18:00 +0200
      Re: [PATCH][RFC] PM / Hibernate: Feed NMI wathdog when creating  snapshot Michal Hocko <mhocko@kernel.org> - 2017-08-16 13:20 +0200
    Re: [PATCH][RFC] PM / Hibernate: Feed NMI wathdog when creating  snapshot Chen Yu <yu.c.chen@intel.com> - 2017-08-16 07:00 +0200

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