Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756176Ab0DOBbZ (ORCPT ); Wed, 14 Apr 2010 21:31:25 -0400 Received: from mail-gy0-f174.google.com ([209.85.160.174]:37628 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753410Ab0DOBbY convert rfc822-to-8bit (ORCPT ); Wed, 14 Apr 2010 21:31:24 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=A3ayDIULRn+iSk1Gg94uZWwqAu4+CGyarlg3m/0LFIeuI50uhkR00GnbBcJ3k43gyw mzXd5v2eRCK7AYxZv28g+PZCrfg1yHnf+njk3nKEYlvVTrRPAwTBVZly14oAvrT0JiYB EIvJxAbOEl4NtlNcvkaO6bARfy3/NIlESOp0U= MIME-Version: 1.0 In-Reply-To: <4BC65237.5080408@kernel.org> References: <9918f566ab0259356cded31fd1dd80da6cae0c2b.1271171877.git.minchan.kim@gmail.com> <20100413154820.GC25756@csn.ul.ie> <4BC65237.5080408@kernel.org> Date: Thu, 15 Apr 2010 10:31:23 +0900 Message-ID: Subject: Re: [PATCH 2/6] change alloc function in pcpu_alloc_pages From: Minchan Kim To: Tejun Heo Cc: Mel Gorman , Andrew Morton , KAMEZAWA Hiroyuki , Bob Liu , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Christoph Lameter Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1389 Lines: 42 Hi, Tejun. On Thu, Apr 15, 2010 at 8:39 AM, Tejun Heo wrote: > Hello, > > On 04/14/2010 12:48 AM, Mel Gorman wrote: >> and the mapping table on x86 at least is based on possible CPUs in >> init_cpu_to_node() leaves the mapping as 0 if the APIC is bad or the numa >> node is reported in apicid_to_node as -1. It would appear on power that >> the node will be 0 for possible CPUs as well. >> >> Hence, I believe this to be safe but a confirmation from Tejun would be >> nice. I would continue digging but this looks like an initialisation path >> so I'll move on to the next patch rather than spending more time. > > This being a pretty cold path, I don't really see much benefit in > converting it to alloc_pages_node_exact().  It ain't gonna make any > difference.  I'd rather stay with the safer / boring one unless > there's a pressing reason to convert. Actually, It's to weed out not-good API usage as well as some performance gain. But I don't think to need it strongly. Okay. Please keep in mind about this and correct it if you confirms it in future. :) > > Thanks. > > -- > tejun > -- Kind regards, Minchan Kim -- 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/