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From: Shaohua Li <shaohua.li@intel.com>
To: Christoph Lameter <cl@linux.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"tj@kernel.org" <tj@kernel.org>,
	"eric.dumazet@gmail.com" <eric.dumazet@gmail.com>
Subject: Re: [patch v2 0/4] percpu_counter: cleanup and fix
Date: Thu, 14 Apr 2011 09:04:13 +0800	[thread overview]
Message-ID: <1302743053.3981.178.camel@sli10-conroe> (raw)
In-Reply-To: <alpine.DEB.2.00.1104130907480.16214@router.home>

On Wed, 2011-04-13 at 22:08 +0800, Christoph Lameter wrote:
> On Wed, 13 Apr 2011, shaohua.li@intel.com wrote:
> 
> > Cleanup percpu_counter code and fix some bugs. The main purpose is to convert
> > percpu_counter to use atomic64, which is useful for workloads which cause
> > percpu_counter->lock contented. In a workload I tested, the atomic method is
> > 50x faster (please see patch 4 for detail).
> 
> Could you post your test and the results please?
the test is very simple, 24 processes in 24 CPU, and each does:
while (1) {
	mmap(128M);
	munmap(128M)
}
we then measure how many loops the process can do.
I'll attach the test in next post.
Just found when I said 50x faster, I actually forgot one other patch's
effect, which is http://marc.info/?l=linux-kernel&m=130127782901127&w=2.
If only having the atomic change, it's about 7x faster. Sorry about
this. I'll add detail data in next post.


      reply	other threads:[~2011-04-14  1:04 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-13  7:57 shaohua.li
2011-04-13  7:57 ` [patch v2 1/4] percpu_counter: change return value and add comments shaohua.li
2011-04-13 19:05   ` Tejun Heo
2011-04-13  7:57 ` [patch v2 2/4] percpu_counter: delete dead code shaohua.li
2011-04-13 18:59   ` Tejun Heo
2011-04-18  0:12   ` Ted Ts'o
2011-04-13  7:57 ` [patch v2 3/4] percpu_counter: fix code for 32bit systems shaohua.li
2011-04-13 19:04   ` Tejun Heo
2011-04-13  7:57 ` [patch v2 4/4] percpu_counter: use atomic64 for counter shaohua.li
2011-04-13 19:07   ` Tejun Heo
2011-04-13 14:08 ` [patch v2 0/4] percpu_counter: cleanup and fix Christoph Lameter
2011-04-14  1:04   ` Shaohua Li [this message]

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