linux-kernel - Re: [FYI] GCC segfaults under heavy multithreaded compilation with AMD Ryzen

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Message-ID: <20170731130435.6cb4f00f@alans-desktop>
Date:   Mon, 31 Jul 2017 13:04:35 +0100
From:   Alan Cox <gnomes@...rguk.ukuu.org.uk>
To:     Satoru Takeuchi <satoru.takeuchi@...il.com>
Cc:     LKML <linux-kernel@...r.kernel.org>, x86@...nel.org
Subject: Re: [FYI] GCC segfaults under heavy multithreaded compilation with
 AMD Ryzen

On Wed, 26 Jul 2017 06:54:01 +0900
Satoru Takeuchi <satoru.takeuchi@...il.com> wrote:

> # I'm a LKML subscriber, but not a x86 list subscriber
> 
> I found the following new linux kernel bugzilla about Ryzen related problem.
> Since many developers don't check this bugzilla and I've also
> encountered this problem,
> I decided to introduce this problem here.

Historically we've seen exactly these symptoms on all kinds of systems
where the memory is at fault, even in cases where memtest86 passes.
Whether there's a specific problem on some Ryzen boards is a question for
AMD, but if I saw this without knowing the CPU I'd suspect memory
firstly. GCC it turns out is by accident an amazingly effective memory
testing tool.

If it is memory corruption problems then no - the kernel cannot work
around that level of hardware failure. The BIOS may be able to if it is a
board or compatibility problem as memory tuning is usually done by the
BIOS.

Alan