linux-kernel - Re: [PATCH v2 4/5] x86/mce: Simplify flow when handling recoverable memory errors

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Date:	Tue, 11 Nov 2014 17:30:59 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	Andy Lutomirski <luto@...capital.net>
Cc:	Chen Gong <gong.chen@...ux.intel.com>, X86 ML <x86@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Oleg Nesterov <oleg@...hat.com>,
	Tony Luck <tony.luck@...el.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 4/5] x86/mce: Simplify flow when handling recoverable
 memory errors

On Tue, Nov 11, 2014 at 08:22:45AM -0800, Andy Lutomirski wrote:
> I think it's okay-ish, but only if it's necessary, and I still don't
> see why it's necessary.
> 
> Can't you just remove TIF_MCE_NOTIFY entirely and just do all the
> mce_notify_process work directly in do_machine_check?  IOW, why do you
> need to store any state per-task when it's already on the stack
> anyway.

I wish but memory_failure() can't run in #MC context as it noodles
quite a lot and grabs all kinds of locks and does a bunch of other
atomit-context-unsafe things.

And it needs to run *before* the process is killed as it looks at its
pages.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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