From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752076AbXDTXxI (ORCPT ); Fri, 20 Apr 2007 19:53:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752082AbXDTXxI (ORCPT ); Fri, 20 Apr 2007 19:53:08 -0400 Received: from mx1.redhat.com ([66.187.233.31]:44487 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752076AbXDTXxH (ORCPT ); Fri, 20 Apr 2007 19:53:07 -0400 Message-ID: <4629524C.5040302@redhat.com> Date: Fri, 20 Apr 2007 19:52:44 -0400 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 1.5.0.7 (X11/20061008) MIME-Version: 1.0 To: Andrew Morton CC: 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> In-Reply-To: <20070420150618.179d31a4.akpm@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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 2 1032 1136 1196 1200 4 1070 1128 2014 2024 8 1000 1088 1665 2087 16 779 1073 1310 1999 -- Politics is the struggle between those who want to make their country the best in the world, and those who believe it already is. Each group calls the other unpatriotic.