From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932825AbVJ3E16 (ORCPT ); Sun, 30 Oct 2005 00:27:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932828AbVJ3E16 (ORCPT ); Sun, 30 Oct 2005 00:27:58 -0400 Received: from smtp209.mail.sc5.yahoo.com ([216.136.130.117]:47255 "HELO smtp209.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S932825AbVJ3E15 (ORCPT ); Sun, 30 Oct 2005 00:27:57 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=Hr/dJEtXP9/D6Z8AKGMMVLzkw7OXZYolyA6YOnpDTC0beItbHHPGx/qhSRmNG2QbxTe2Lk5pC39QkRQiB8QtJhgiKPiVTiAF0GzMWHwV2xABXHpV05mO9WjFsekvcmHfuhgc09qmo6GyeTyy0uzy3cnHI4NcVu91CUKJTLHH+Ro= ; Message-ID: <43644C22.8050501@yahoo.com.au> Date: Sun, 30 Oct 2005 15:29:22 +1100 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Hugh Dickins CC: Robin Holt , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: munmap extremely slow even with untouched mapping. References: <20051028013738.GA19727@attica.americas.sgi.com> <43620138.6060707@yahoo.com.au> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hugh Dickins wrote: > Yes, it's a good observation from Robin. > > It'll have been spoiling the exit speedup we expected from your > 2.6.14 copy_page_range "Don't copy [faultable] ptes" fork speedup. > Yep. Not to mention it is probably responsible for some of the 4 level page table performance slowdowns on x86-64. > > > I prefer your patch too. But I'm not very interested in temporary > speedups relative to 2.6.14. Attacking this is a job I'd put off > until after the page fault scalability changes, which make it much > easier to do a proper job. > Yeah definitely. I wonder if we should go with Robin's fix (+/- my variation) as a temporary measure for 2.6.15? -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com