linux-kernel - Re: [PATCH] seqlock: don't smp_rmb in seqlock reader spin loop

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20110512140832.GK6008@one.firstfloor.org>
Date:	Thu, 12 May 2011 16:08:32 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Milton Miller <miltonm@....com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Nick Piggin <npiggin@...nel.dk>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Anton Blanchard <anton@...ba.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Eric Dumazet <eric.dumazet@...il.com>,
	linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
	Ingo Molnar <mingo@...e.hu>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andi Kleen <andi@...stfloor.org>
Subject: Re: [PATCH] seqlock: don't smp_rmb in seqlock reader spin loop

On Thu, May 12, 2011 at 04:13:54AM -0500, Milton Miller wrote:
> 
> Move the smp_rmb after cpu_relax loop in read_seqlock and add
> ACCESS_ONCE to make sure the test and return are consistent.
> 
> A multi-threaded core in the lab didn't like the update

Which core was that?

-Andi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/