linux-kernel - Re: [RFC PATCH 5/5] x86/mce: Handle AMD threshold interrupt storms

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Date:   Fri, 8 Apr 2022 12:29:24 -0700
From:   "Luck, Tony" <tony.luck@...el.com>
To:     "Koralahalli Channabasappa, Smita" <skoralah@....com>
Cc:     Smita Koralahalli <Smita.KoralahalliChannabasappa@....com>,
        Borislav Petkov <bp@...en8.de>,
        "hpa@...or.com" <hpa@...or.com>,
        Yazen Ghannam <yazen.ghannam@....com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "linux-edac@...r.kernel.org" <linux-edac@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "x86@...nel.org" <x86@...nel.org>
Subject: Re: [RFC PATCH 5/5] x86/mce: Handle AMD threshold interrupt storms

On Fri, Apr 08, 2022 at 02:48:47AM -0500, Koralahalli Channabasappa, Smita wrote:
> Hi,
> 
> On 4/6/22 5:44 PM, Luck, Tony wrote:
> 
> > +		/* Return early on an interrupt storm */
> > +		if (this_cpu_read(bank_storm[bank]))
> > +			return;
> > 
> > Is you reasoning for early return that you already have plenty of
> > logged errors from this bank, so OK to skip additional processing
> > of this one?
> 
> The idea behind this was: Once, the interrupts are turned off by
> track_cmci_storm() on a storm, (which is called before this "if
> statement") logging and handling of subsequent corrected errors
> will be taken care by machine_check_poll(). Hence, no need to
> redo this again in the handler....
> 
> Let me know what are your thoughts on this?

Makes sense. There's a storm, so picking up this error now,
or waiting for machine_check_poll() to get it makes little
difference.

-Tony