From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933171Ab3HNU0H (ORCPT ); Wed, 14 Aug 2013 16:26:07 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54705 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933148Ab3HNU0E (ORCPT ); Wed, 14 Aug 2013 16:26:04 -0400 Date: Wed, 14 Aug 2013 13:26:02 -0700 From: Andrew Morton To: Minchan Kim Cc: Mel Gorman , Xishi Qiu , riel@redhat.com, aquini@redhat.com, linux-mm@kvack.org, LKML Subject: Re: [PATCH] mm: skip the page buddy block instead of one page Message-Id: <20130814132602.814a88e991e29c5b93bbe22c@linux-foundation.org> In-Reply-To: <20130814155205.GA2706@gmail.com> References: <520B0B75.4030708@huawei.com> <20130814085711.GK2296@suse.de> <20130814155205.GA2706@gmail.com> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 15 Aug 2013 00:52:29 +0900 Minchan Kim wrote: > On Wed, Aug 14, 2013 at 09:57:11AM +0100, Mel Gorman wrote: > > On Wed, Aug 14, 2013 at 12:45:41PM +0800, Xishi Qiu wrote: > > > A large free page buddy block will continue many times, so if the page > > > is free, skip the whole page buddy block instead of one page. > > > > > > Signed-off-by: Xishi Qiu > > > > page_order cannot be used unless zone->lock is held which is not held in > > this path. Acquiring the lock would prevent parallel allocations from the > > Argh, I missed that. I missed it as well. And so did Xishi Qiu. Mel, we have a problem. What can we do to make this code more maintainable?