linux-kernel - Re: [PATCH] x86/mce: Lower throttling MCE messages to warnings

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Date:   Fri, 11 Oct 2019 09:31:05 +0200
From:   Benjamin Berg <bberg@...hat.com>
To:     Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        Borislav Petkov <bp@...en8.de>
Cc:     linux-kernel@...r.kernel.org, Hans de Goede <hdegoede@...hat.com>,
        Christian Kellner <ckellner@...hat.com>,
        Tony Luck <tony.luck@...el.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        linux-edac@...r.kernel.org
Subject: Re: [PATCH] x86/mce: Lower throttling MCE messages to warnings

Hi Srinivas,

On Thu, 2019-10-10 at 14:08 -0700, Srinivas Pandruvada wrote:
> I have a patch to address this. Instead of avoiding any critical
> warnings or wait for 300 seconds for next one, the warning is based on
> how long the system is working on throttled condition. If for example
> the fan broke, then the throttling is extended for a long time. Then we
> better warn.
> I am waiting for internal review, and hope to post by tomorrow.

Nice! I agree that a heuristic seems better than the very simple
approach taken in this patch.

Thanks,
Benjamin

> Thanks
> Srinivas
> 
> > > Signed-off-by: Benjamin Berg <bberg@...hat.com>
> > > Tested-by: Christian Kellner <ckellner@...hat.com>
> > > ---
> > >  arch/x86/kernel/cpu/mce/therm_throt.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/arch/x86/kernel/cpu/mce/therm_throt.c
> > > b/arch/x86/kernel/cpu/mce/therm_throt.c
> > > index 6e2becf547c5..bc441d68d060 100644
> > > --- a/arch/x86/kernel/cpu/mce/therm_throt.c
> > > +++ b/arch/x86/kernel/cpu/mce/therm_throt.c
> > > @@ -188,7 +188,7 @@ static void therm_throt_process(bool
> > > new_event,
> > > int event, int level)
> > >  	/* if we just entered the thermal event */
> > >  	if (new_event) {
> > >  		if (event == THERMAL_THROTTLING_EVENT)
> > > -			pr_crit("CPU%d: %s temperature above threshold,
> > > cpu clock throttled (total events = %lu)\n",
> > > +			pr_warn("CPU%d: %s temperature above threshold,
> > > cpu clock throttled (total events = %lu)\n",
> > >  				this_cpu,
> > >  				level == CORE_LEVEL ? "Core" :
> > > "Package",
> > >  				state->count);
> > > -- 
> > 
> > This has carried over since its very first addition in
> > 
> > commit 3867eb75b9279c7b0f6840d2ad9f27694ba6c4e4
> > Author: Dave Jones <davej@...e.de>
> > Date:   Tue Apr 2 20:02:27 2002 -0800
> > 
> >     [PATCH] x86 bluesmoke update.
> >     
> >     o  Make MCE compile time optional       (Paul Gortmaker)
> >     o  P4 thermal trip monitoring.          (Zwane Mwaikambo)
> >     o  Non-fatal MCE logging.               (Me)
> > 
> > 
> > It used to be KERN_EMERG back then, though.
> > 
> > And yes, this issue has come up in the past already so I think I'll
> > take
> > it. I'll just give Intel folks a couple of days to object should
> > there
> > be anything to object to.
> > 
> > Thx.
> >