From: Alex Shi <alex.shi@intel.com>
To: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Andi Kleen <andi@firstfloor.org>,
Michel Lespinasse <walken@google.com>,
Davidlohr Bueso <davidlohr.bueso@hp.com>,
Matthew R Wilcox <matthew.r.wilcox@intel.com>,
Dave Hansen <dave.hansen@intel.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Rik van Riel <riel@redhat.com>,
Peter Hurley <peter@hurleysoftware.com>,
linux-kernel@vger.kernel.org, linux-mm <linux-mm@kvack.org>
Subject: Re: [PATCH v4 1/5] rwsem: check the lock before cpmxchg in down_write_trylock
Date: Thu, 27 Jun 2013 09:32:33 +0800 [thread overview]
Message-ID: <51CB9631.1030508@intel.com> (raw)
In-Reply-To: <1372285674.22432.141.camel@schen9-DESK>
The following line should be added head of commit log on patches 1~4. :)
From: Alex Shi <alex.shi@intel.com>
> Cmpxchg will cause the cacheline bouning when do the value checking,
> that cause scalability issue in a large machine (like a 80 core box).
>
> So a lock pre-read can relief this contention.
>
> Signed-off-by: Alex Shi <alex.shi@intel.com>
--
Thanks
Alex
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next prev parent reply other threads:[~2013-06-27 1:32 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1372282738.git.tim.c.chen@linux.intel.com>
2013-06-26 22:27 ` Tim Chen
2013-06-27 1:32 ` Alex Shi [this message]
2013-06-27 15:59 ` Tim Chen
2013-06-26 22:27 ` [PATCH v4 2/5] rwsem: remove 'out' label in do_wake Tim Chen
2013-06-26 22:28 ` [PATCH v4 3/5] rwsem: remove try_reader_grant label do_wake Tim Chen
2013-06-26 22:28 ` [PATCH v4 4/5] rwsem/wake: check lock before do atomic update Tim Chen
2013-06-26 22:28 ` [PATCH v4 5/5] rwsem: do optimistic spinning for writer lock acquisition Tim Chen
2013-06-26 22:40 ` Davidlohr Bueso
2013-06-26 22:56 ` Tim Chen
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