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From: Balbir Singh <balbir@linux.vnet.ibm.com>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
	"nishimura@mxp.nes.nec.co.jp" <nishimura@mxp.nes.nec.co.jp>
Subject: Re: [RFC][PATCH 0/4][mmotm] memcg: reduce lock contention v3
Date: Thu, 10 Sep 2009 02:00:42 +0530	[thread overview]
Message-ID: <20090909203042.GA4473@balbir.in.ibm.com> (raw)
In-Reply-To: <20090909173903.afc86d85.kamezawa.hiroyu@jp.fujitsu.com>

* KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> [2009-09-09 17:39:03]:

> This patch series is for reducing memcg's lock contention on res_counter, v3.
> (sending today just for reporting current status in my stack.)
> 
> It's reported that memcg's res_counter can cause heavy false sharing / lock
> conention and scalability is not good. This is for relaxing that.
> No terrible bugs are found, I'll maintain/update this until the end of next
> merge window. Tests on big-smp and new-good-idea are welcome.
> 
> This patch is on to mmotm+Nishimura's fix + Hugh's get_user_pages() patch.
> But can be applied directly against mmotm, I think.
> 
> numbers:
> 
> I used 8cpu x86-64 box and run make -j 12 kernel.
> Before make, make clean and drop_caches.
>

Kamezawa-San

I was able to test on a 24 way using my parallel page fault test
program and here is what I see

 Performance counter stats for '/home/balbir/parallel_pagefault' (3
runs):

 7191673.834385  task-clock-msecs         #     23.953 CPUs    ( +- 0.001% )
         427765  context-switches         #      0.000 M/sec   ( +- 0.106% )
            234  CPU-migrations           #      0.000 M/sec   ( +- 20.851% )
       87975343  page-faults              #      0.012 M/sec   ( +- 0.347% )
  5962193345280  cycles                   #    829.041 M/sec   ( +- 0.012% )
  1009132401195  instructions             #      0.169 IPC     ( +- 0.059% )
    10068652670  cache-references         #      1.400 M/sec   ( +- 2.581% )
     2053688394  cache-misses             #      0.286 M/sec   ( +- 0.481% )

  300.238748326  seconds time elapsed   ( +-   0.001% )

Without the patch I saw

 Performance counter stats for '/home/balbir/parallel_pagefault' (3
runs):

 7198364.596593  task-clock-msecs         #     23.959 CPUs    ( +- 0.004% )
         425104  context-switches         #      0.000 M/sec   ( +- 0.244% )
            157  CPU-migrations           #      0.000 M/sec   ( +- 13.291% )
       28964117  page-faults              #      0.004 M/sec   ( +- 0.106% )
  5786854402292  cycles                   #    803.912 M/sec   ( +- 0.013% )
   835828892399  instructions             #      0.144 IPC     ( +- 0.073% )
     6240606753  cache-references         #      0.867 M/sec   ( +- 1.058% )
     2068445332  cache-misses             #      0.287 M/sec   ( +- 1.844% )

  300.443366784  seconds time elapsed   ( +-   0.005% )


This does look like a very good improvement.



 
-- 
	Balbir

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  parent reply	other threads:[~2009-09-09 20:31 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-09  8:39 [RFC][PATCH 0/4][mmotm] memcg: reduce lock contention v3 KAMEZAWA Hiroyuki
2009-09-09  8:41 ` [RFC][PATCH 1/4][mmotm] memcg: soft limit clean up KAMEZAWA Hiroyuki
     [not found]   ` <661de9470909090410t160454a2k658c980b92d11612@mail.gmail.com>
2009-09-10  0:10     ` KAMEZAWA Hiroyuki
2009-09-09  8:41 ` [RFC][PATCH 2/4][mmotm] clean up charge path of softlimit KAMEZAWA Hiroyuki
2009-09-09  8:44 ` [RFC][PATCH 3/4][mmotm] memcg: batched uncharge KAMEZAWA Hiroyuki
2009-09-09  8:45 ` [RFC][PATCH 4/4][mmotm] memcg: coalescing charge KAMEZAWA Hiroyuki
2009-09-12  4:58   ` Daisuke Nishimura
2009-09-15  0:09     ` KAMEZAWA Hiroyuki
2009-09-09 20:30 ` Balbir Singh [this message]
2009-09-10  0:20   ` [RFC][PATCH 0/4][mmotm] memcg: reduce lock contention v3 KAMEZAWA Hiroyuki
2009-09-10  5:18     ` Balbir Singh
2009-09-18  8:47 ` [RFC][PATCH 0/11][mmotm] memcg: patch dump (Sep/18) KAMEZAWA Hiroyuki
2009-09-18  8:50   ` [RFC][PATCH 1/11] memcg: clean up softlimit uncharge KAMEZAWA Hiroyuki
2009-09-18  8:52   ` [RFC][PATCH 2/11]memcg: reduce res_counter_soft_limit_excess KAMEZAWA Hiroyuki
2009-09-18  8:53   ` [RFC][PATCH 3/11] memcg: coalescing uncharge KAMEZAWA Hiroyuki
2009-09-18  8:54   ` [RFC][PATCH 4/11] memcg: coalescing charge KAMEZAWA Hiroyuki
2009-09-18  8:55   ` [RFC][PATCH 5/11] memcg: clean up cancel charge KAMEZAWA Hiroyuki
2009-09-18  8:57   ` [RFC][PATCH 6/11] memcg: cleaun up percpu statistics KAMEZAWA Hiroyuki
2009-09-18  8:58   ` [RFC][PATCH 7/11] memcg: rename from_cont to from_cgroup KAMEZAWA Hiroyuki
2009-09-18  9:00   ` [RFC][PATCH 8/11]memcg: remove unused macro and adds commentary KAMEZAWA Hiroyuki
2009-09-18  9:01   ` [RFC][PATCH 9/11]memcg: clean up zonestat funcs KAMEZAWA Hiroyuki
2009-09-18  9:04   ` [RFC][PATCH 10/11][mmotm] memcg: clean up percpu and more commentary for soft limit KAMEZAWA Hiroyuki
2009-09-18  9:06   ` [RFC][PATCH 11/11][mmotm] memcg: more commentary and clean up KAMEZAWA Hiroyuki
2009-09-18 10:37   ` [RFC][PATCH 0/11][mmotm] memcg: patch dump (Sep/18) Daisuke Nishimura

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