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.
next prev parent reply other threads:[~2009-11-23 14:40 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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