linux-kernel - Re: [PATCH v2] x86/mce: Always save severity in machine_check

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Date:   Thu, 22 Jun 2017 10:48:44 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Yazen Ghannam <Yazen.Ghannam@....com>
Cc:     linux-edac@...r.kernel.org, Tony Luck <tony.luck@...el.com>,
        x86@...nel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] x86/mce: Always save severity in machine_check_poll

On Wed, Jun 21, 2017 at 02:46:42PM -0500, Yazen Ghannam wrote:
> From: Yazen Ghannam <yazen.ghannam@....com>
> 
> The severity gives a hint as to how to handle the error. The notifier
> blocks can then use the severity to decide on an action. It's not necessary
> for machine_check_poll() to filter errors for the notifier chain, since
> each block will check its own set of conditions before handling an error.
> Also, there isn't any urgency for machine_check_poll() to make decisions
> based on severity like in do_machine_check().
> 
> If we can assume that a severity is set then we can use them in more
> notifier blocks. For example, the CEC block can check for a "KEEP" severity

Hmm, I'm not sure about this. If we did this, we would have to *make*
CECCs be always KEEP severity. And they are now but doing that would
make that mapping CECC->KEEP imprecise and unnecessary but required....

Yeah, we can talk about that when we have to cross that bridge.

So I've left the example but made the above s/can/could/ :)

> rather than checking bits in the status. This isn't possible now since the
> severity is not set except for "DEFFRRED/UCNA" errors with a valid address.
> 
> Save the severity since we have it, and let the notifier blocks decide if
> they want to do anything.
> 
> Signed-off-by: Yazen Ghannam <yazen.ghannam@....com>
> ---
> Link:
> https://lkml.kernel.org/r/1497286446-59533-1-git-send-email-Yazen.Ghannam@amd.com
> 
> v1->v2:
> * Expand commit message.
> 
>  arch/x86/kernel/cpu/mcheck/mce.c | 7 +------
>  1 file changed, 1 insertion(+), 6 deletions(-)

Applied, thanks.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.