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Date: Sat, 25 Jul 2015 11:03:40 +0200
From: Borislav Petkov <bp@alien8.de>
To: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
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Subject: Re: [PATCH v4 1/3] x86/ldt: Make modify_ldt synchronous
Message-ID: <20150725090340.GD3427@nazgul.tnic>
References: <cover.1437802102.git.luto@kernel.org>
 <12ddcec938d76238975dff9de7d66cfc6e574aa7.1437802102.git.luto@kernel.org>
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On Fri, Jul 24, 2015 at 10:36:44PM -0700, Andy Lutomirski wrote:
> modify_ldt has questionable locking and does not synchronize
> threads.  Improve it: redesign the locking and synchronize all
> threads' LDTs using an IPI on all modifications.
> 
> This will dramatically slow down modify_ldt in multithreaded
> programs, but there shouldn't be any multithreaded programs that
> care about modify_ldt's performance in the first place.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Andy Lutomirski <luto@kernel.org>

Reviewed-by: Borislav Petkov <bp@suse.de>

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--