From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932167AbXDUAst (ORCPT ); Fri, 20 Apr 2007 20:48:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932185AbXDUAst (ORCPT ); Fri, 20 Apr 2007 20:48:49 -0400 Received: from gw1.cosmosbay.com ([86.65.150.130]:34769 "EHLO gw1.cosmosbay.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932167AbXDUAss (ORCPT ); Fri, 20 Apr 2007 20:48:48 -0400 Message-ID: <46295F59.8000506@cosmosbay.com> Date: Sat, 21 Apr 2007 02:48:25 +0200 From: Eric Dumazet User-Agent: Thunderbird 1.5.0.10 (Windows/20070221) MIME-Version: 1.0 To: Rik van Riel CC: Andrew Morton , linux-kernel , linux-mm , shak Subject: Re: [PATCH] lazy freeing of memory through MADV_FREE References: <46247427.6000902@redhat.com> <20070420135715.f6e8e091.akpm@linux-foundation.org> <462932BE.4020005@redhat.com> <20070420150618.179d31a4.akpm@linux-foundation.org> <4629524C.5040302@redhat.com> In-Reply-To: <4629524C.5040302@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.6 (gw1.cosmosbay.com [86.65.150.130]); Sat, 21 Apr 2007 02:48:33 +0200 (CEST) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Rik van Riel a écrit : > Andrew Morton wrote: >> On Fri, 20 Apr 2007 17:38:06 -0400 >> Rik van Riel wrote: >> >>> Andrew Morton wrote: >>> >>>> I've also merged Nick's "mm: madvise avoid exclusive mmap_sem". >>>> >>>> - Nick's patch also will help this problem. It could be that your >>>> patch >>>> no longer offers a 2x speedup when combined with Nick's patch. >>>> >>>> It could well be that the combination of the two is even better, >>>> but it >>>> would be nice to firm that up a bit. >>> I'll test that. >> >> Thanks. > > Well, good news. > > It turns out that Nick's patch does not improve peak > performance much, but it does prevent the decline when > running with 16 threads on my quad core CPU! > > We _definately_ want both patches, there's a huge benefit > in having them both. > > Here are the transactions/seconds for each combination: > > vanilla new glibc madv_free kernel madv_free + mmap_sem > threads > > 1 610 609 596 545 545 tps versus 610 tps for one thread ? It seems quite bad, no ? Could you please find an explanation for this ? > 2 1032 1136 1196 1200 > 4 1070 1128 2014 2024 > 8 1000 1088 1665 2087 > 16 779 1073 1310 1999 > > Thank you