Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754890AbZCHVxf (ORCPT ); Sun, 8 Mar 2009 17:53:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754092AbZCHVx0 (ORCPT ); Sun, 8 Mar 2009 17:53:26 -0400 Received: from smtp-out.google.com ([216.239.33.17]:3271 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753037AbZCHVxZ (ORCPT ); Sun, 8 Mar 2009 17:53:25 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id: references:user-agent:mime-version:content-type:x-system-of-record; b=HeA5oxLuI6l93k81P7Rca3HG0fj6OjC2oxxwNATU0w7DKuWANu3XuZOLl09Qecp9+ I7P5G9eYZ93U+7j1c6wrg== Date: Sun, 8 Mar 2009 14:51:58 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Matt Mackall cc: Andrew Morton , Christoph Lameter , Pekka Enberg , Paul Menage , Randy Dunlap , linux-kernel@vger.kernel.org Subject: Re: [patch -mm] cpusets: add memory_slab_hardwall flag In-Reply-To: <1236531664.4192.389.camel@calx> Message-ID: References: <1236531664.4192.389.camel@calx> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1399 Lines: 39 On Sun, 8 Mar 2009, Matt Mackall wrote: > > For slob, if the page from the slob list is not from an allowable node, > > we continue to scan for an appropriate slab. If none can be used, a new > > slab is allocated. > > Looks fine to me, if a little expensive. Is that your acked-by? :) It's not expensive for cpusets that do not set memory_slab_hardwall, which is disabled by default, other than some cacheline polluting. If the option is set, then the performance penalty is described in the documentation and should be assumed by the user. We currently have a couple different ways to check for a task's cpuset options: - per-task flags such as PF_SPREAD_PAGE and PF_SPREAD_SLAB used in the hotpath, and - rcu dereferencing current's cpuset and atomically checking a cpuset flag bit. It would be nice to unify these to free up some task flag bits. > We'll be needing SLQB support > though. > Yeah, I'd like to add the necessary slqb support from Pekka's git tree but this patch depends on cpusets-replace-zone-allowed-functions-with-node-allowed.patch in -mm, so we'll need to know the route by which this should be pushed. -- 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/