From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751246AbWGCTge (ORCPT ); Mon, 3 Jul 2006 15:36:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751248AbWGCTge (ORCPT ); Mon, 3 Jul 2006 15:36:34 -0400 Received: from mx2.suse.de ([195.135.220.15]:50861 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S1751246AbWGCTge (ORCPT ); Mon, 3 Jul 2006 15:36:34 -0400 From: Andi Kleen To: eranian@hpl.hp.com Subject: Re: [PATCH 10/17] 2.6.17.1 perfmon2 patch for review: PMU context switch Date: Mon, 3 Jul 2006 21:36:28 +0200 User-Agent: KMail/1.9.3 Cc: linux-kernel@vger.kernel.org References: <200606230913.k5N9D73v032387@frankl.hpl.hp.com> <200607032125.48727.ak@suse.de> <20060703192212.GC5471@frankl.hpl.hp.com> In-Reply-To: <20060703192212.GC5471@frankl.hpl.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200607032136.28068.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Monday 03 July 2006 21:22, Stephane Eranian wrote: > Andi, > > On Mon, Jul 03, 2006 at 09:25:48PM +0200, Andi Kleen wrote: > > On Monday 03 July 2006 11:49, Stephane Eranian wrote: > > > Andi, > > > > > > Here is a first cut at the patch to simplify the context > > > switch for the common case and also touch 2 cachelines (instead of 3). > > > There are 2 new TIF flags. I just tried this on x86_64 but I believe > > > we could do the same on i386. > > > > > > Is that what you were thinking about? > > > > Yes, looks good. > > > I have worked on this some more and I also looked at i386. > They seem to handle the io bitmap differently there. At least > they seem to have some lazy scheme whereby you do not reinstall > if new task is the last owner of tss. Is there a reason for not > having this in place for x86-64? There was a reason but I can't remember it right now :/ Something in the new scheme didn't fit well or it was just too complicated. -Andi