From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751103AbWFBESz (ORCPT ); Fri, 2 Jun 2006 00:18:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751107AbWFBESy (ORCPT ); Fri, 2 Jun 2006 00:18:54 -0400 Received: from smtp107.mail.mud.yahoo.com ([209.191.85.217]:30890 "HELO smtp107.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S1751105AbWFBESx (ORCPT ); Fri, 2 Jun 2006 00:18:53 -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=i1xCQEwaLGRz2gYZ+eVDhS0+LHPc6Cwlr0ymF0ZjN/ZdL2wvMfRq+gaYrCZV6yR3KyzO8POTHfxew2C0fKzN/ZtAe5gtZWx1uTtIcRWIAjwn6Aw8NkGSrw5OFiUZdUjcuzSVI22Nu5cuiIOozftqpiQ4+qiRd6rx0g1vd2hMx8c= ; Message-ID: <447FBC28.8030401@yahoo.com.au> Date: Fri, 02 Jun 2006 14:18:48 +1000 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: Con Kolivas CC: linux-kernel@vger.kernel.org, "Chen, Kenneth W" , "'Chris Mason'" , Ingo Molnar Subject: Re: [PATCH RFC] smt nice introduces significant lock contention References: <000101c685d7$1bc84390$d234030a@amr.corp.intel.com> <200606021159.06519.kernel@kolivas.org> <200606021228.37910.kernel@kolivas.org> <200606021355.23671.kernel@kolivas.org> In-Reply-To: <200606021355.23671.kernel@kolivas.org> 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 Con Kolivas wrote: > On Friday 02 June 2006 12:28, Con Kolivas wrote: > >>Actually looking even further, we only introduced the extra lookup of the >>next task when we started unlocking the runqueue in schedule(). Since we >>can get by without locking this_rq in schedule with this approach we can >>simplify dependent_sleeper even further by doing the dependent sleeper >>check after we have discovered what next is in schedule and avoid looking >>it up twice. I'll hack something up to do that soon. > > > Something like this (sorry I couldn't help but keep hacking on it). Looking pretty good. Nice to acknowledge Chris's idea for trylocks in your changelog when you submit a final patch. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com