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From: Tejun Heo <tj@kernel.org>
To: Shaohua Li <shaohua.li@intel.com>
Cc: lkml <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	"cl@linux.com" <cl@linux.com>
Subject: Re: [PATCH 4/4]percpu_counter: use atomic64 for counter
Date: Wed, 13 Apr 2011 12:11:30 +0900	[thread overview]
Message-ID: <20110413031130.GH16342@mtj.dyndns.org> (raw)
In-Reply-To: <1302657428.3981.149.camel@sli10-conroe>

Hello,

On Wed, Apr 13, 2011 at 09:17:08AM +0800, Shaohua Li wrote:
> yes, we do have something this matters. the vm_committed_as
> percpu_counter could heavily contend the lock. please see
> http://marc.info/?l=linux-kernel&m=130144786026044&w=2
> We should fix vm_committed_as, but the atomic method also gives me very
> good output. When I do mmap/munmap test in a 24 CPU system, the atomic
> method gives me 50x faster.

That's good to hear.  Care to provide the performance info in the
commit message too?

Thanks.

-- 
tejun

      reply	other threads:[~2011-04-13  3:11 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-12  8:04 [PATCH 4/4]percpu_counter: use atomic64 for counter Shaohua Li
2011-04-12 19:15 ` Tejun Heo
2011-04-13  1:17   ` Shaohua Li
2011-04-13  3:11     ` Tejun Heo [this message]

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