From: Christoph Lameter <cl@linux-foundation.org>
To: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
"hugh.dickins@tiscali.co.uk" <hugh.dickins@tiscali.co.uk>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org, Tejun Heo <tj@kernel.org>,
Andi Kleen <andi@firstfloor.org>
Subject: Re: [MM] Make mm counters per cpu instead of atomic
Date: Mon, 23 Nov 2009 08:31:40 -0600 (CST) [thread overview]
Message-ID: <alpine.DEB.2.00.0911230830300.26432@router.home> (raw)
In-Reply-To: <1258966270.29789.45.camel@localhost>
On Mon, 23 Nov 2009, Zhang, Yanmin wrote:
> Another theoretic issue is below scenario:
> Process A get the read lock on cpu 0 and is scheduled to cpu 2 to unlock. Then
> it's scheduled back to cpu 0 to repeat the step. eventually, the reader counter
> will overflow. Considering multiple thread cases, it might be faster to
> overflow than what we imagine. When it overflows, processes will hang there.
True.... We need to find some alternative to per cpu data to scale mmap
sem then.
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next prev parent reply other threads:[~2009-11-23 14:32 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-04 19:14 Christoph Lameter
2009-11-04 19:17 ` [MM] Remove rss batching from copy_page_range() Christoph Lameter
2009-11-04 21:02 ` Andi Kleen
2009-11-04 22:02 ` Christoph Lameter
2009-11-05 8:27 ` Andi Kleen
2009-11-04 21:01 ` [MM] Make mm counters per cpu instead of atomic Andi Kleen
2009-11-04 23:49 ` Dave Jones
2009-11-05 15:04 ` Christoph Lameter
2009-11-05 15:36 ` [MM] Make mm counters per cpu instead of atomic V2 Christoph Lameter
2009-11-06 1:11 ` KAMEZAWA Hiroyuki
2009-11-06 3:23 ` KAMEZAWA Hiroyuki
2009-11-06 17:32 ` Christoph Lameter
2009-11-06 19:03 ` KAMEZAWA Hiroyuki
2009-11-06 19:13 ` Christoph Lameter
2009-11-06 19:20 ` KAMEZAWA Hiroyuki
2009-11-06 19:47 ` Christoph Lameter
2009-11-10 22:44 ` Andrew Morton
2009-11-10 23:20 ` Christoph Lameter
2009-11-06 4:08 ` KAMEZAWA Hiroyuki
2009-11-06 4:15 ` KAMEZAWA Hiroyuki
2009-11-05 1:16 ` [MM] Make mm counters per cpu instead of atomic KAMEZAWA Hiroyuki
2009-11-05 15:10 ` Christoph Lameter
2009-11-05 23:42 ` KAMEZAWA Hiroyuki
2009-11-17 6:48 ` Zhang, Yanmin
2009-11-17 7:31 ` Zhang, Yanmin
2009-11-17 9:34 ` Zhang, Yanmin
2009-11-17 17:25 ` Christoph Lameter
2009-11-19 0:48 ` Zhang, Yanmin
2009-11-23 8:51 ` Zhang, Yanmin
2009-11-23 14:31 ` Christoph Lameter [this message]
2009-11-24 8:02 ` Zhang, Yanmin
2009-11-24 15:17 ` Christoph Lameter
2009-11-25 1:23 ` Zhang, Yanmin
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