Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752948AbZJEOt7 (ORCPT ); Mon, 5 Oct 2009 10:49:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752387AbZJEOt6 (ORCPT ); Mon, 5 Oct 2009 10:49:58 -0400 Received: from smtp2.ultrahosting.com ([74.213.174.253]:49396 "EHLO smtp.ultrahosting.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752525AbZJEOt6 (ORCPT ); Mon, 5 Oct 2009 10:49:58 -0400 Date: Mon, 5 Oct 2009 10:43:12 -0400 (EDT) From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Mel Gorman cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Tejun Heo , mingo@elte.hu, rusty@rustcorp.com.au, Pekka Enberg Subject: Re: [this_cpu_xx V4 13/20] this_cpu_ops: page allocator conversion In-Reply-To: <20091005094527.GB12681@csn.ul.ie> Message-ID: References: <20091001212521.123389189@gentwo.org> <20091001212600.068637154@gentwo.org> <20091002151437.GP21906@csn.ul.ie> <20091005094527.GB12681@csn.ul.ie> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1208 Lines: 34 On Mon, 5 Oct 2009, Mel Gorman wrote: > > Right. WE need to move the local_irq_save() up two lines. > > Just so I'm 100% clear, IRQ disabling is considered a preemption point? Yes. > > Move disable interrupts before the this_cpu_ptr? > > > > In this case, why not move this_cpu_ptr() down until its first use just > before the if (cold) check? It'll still be within the IRQ disabling but > without significantly increasing the amount of time the IRQ is disabled. Good idea. Ill put that into the next release. > > > > + * Before this call only boot pagesets were available. > > > > + * Boot pagesets will no longer be used after this call is complete. > > > > > > If they are no longer used, do we get the memory back? > > > > No we need to keep them for onlining new processors. > > > > That comment would appear to disagree. The comment is accurate for a processor. Once the pagesets are allocated for a processor then the boot pageset is no longer used. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/