From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754004Ab1AYVIs (ORCPT ); Tue, 25 Jan 2011 16:08:48 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:46292 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753167Ab1AYVIr convert rfc822-to-8bit (ORCPT ); Tue, 25 Jan 2011 16:08:47 -0500 Subject: Re: [PATCH 00/25] mm: Preemptibility -v7 From: Peter Zijlstra To: Andi Kleen Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Hugh Dickins , benh In-Reply-To: <4D3F36CB.6060505@linux.intel.com> References: <20110125173111.720927511@chello.nl> <1295987985.28776.1118.camel@laptop> <4D3F36CB.6060505@linux.intel.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Tue, 25 Jan 2011 22:09:30 +0100 Message-ID: <1295989770.28776.1127.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2011-01-25 at 12:47 -0800, Andi Kleen wrote: > > I thought the reason for the preempt off inside the mmu gather region was > to stay on the same CPU for local/remote flushes. How would it change that? afaik its been preempt-off solely because it was always inside a number of spinlocks, I know both Hugh and BenH worked on making it preemptible far before I started this. I remember Hugh and Nick talking about this at OLS'06 or 07, can't really remember. As to local/remote flushes, there is no real saying where the pages came from due to on-demand paging and the scheduler never having had a notion of home-node. Therefore freeing them wouldn't be more of less local if that is exposed to the same migration as allocation was.