From: Christoph Lameter <cl@linux.com>
To: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: linux-mm@kvack.org, Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>,
Noam Camus <noamc@ezchip.com>,
stable@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-snps-arc@lists.infradead.org
Subject: Re: [PATCH] mm: slub: Ensure that slab_unlock() is atomic
Date: Tue, 8 Mar 2016 09:00:57 -0600 (CST) [thread overview]
Message-ID: <alpine.DEB.2.20.1603080857360.4047@east.gentwo.org> (raw)
In-Reply-To: <1457447457-25878-1-git-send-email-vgupta@synopsys.com>
On Tue, 8 Mar 2016, Vineet Gupta wrote:
> This in turn happened because slab_unlock() doesn't serialize properly
> (doesn't use atomic clear) with a concurrent running
> slab_lock()->test_and_set_bit()
This is intentional because of the increased latency of atomic
instructions. Why would the unlock need to be atomic? This patch will
cause regressions.
Guess this is an architecture specific issue of modified
cachelines not becoming visible to other processors?
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next prev parent reply other threads:[~2016-03-08 15:01 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-08 14:30 Vineet Gupta
2016-03-08 15:00 ` Christoph Lameter [this message]
2016-03-08 15:46 ` Vineet Gupta
2016-03-08 20:40 ` Christoph Lameter
2016-03-09 6:43 ` Vineet Gupta
2016-03-09 10:13 ` Peter Zijlstra
2016-03-09 10:31 ` Peter Zijlstra
2016-03-09 11:12 ` Vineet Gupta
2016-03-09 11:00 ` Vineet Gupta
2016-03-09 11:40 ` Peter Zijlstra
2016-03-09 11:53 ` Vineet Gupta
2016-03-09 12:22 ` Peter Zijlstra
2016-03-14 8:05 ` Vineet Gupta
2016-03-09 13:22 ` Vineet Gupta
2016-03-09 14:51 ` Peter Zijlstra
2016-03-10 5:51 ` Vineet Gupta
2016-03-10 9:10 ` Peter Zijlstra
2016-03-08 15:32 ` Vlastimil Babka
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