From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx143.postini.com [74.125.245.143]) by kanga.kvack.org (Postfix) with SMTP id 51E0A6B0089 for ; Wed, 14 Aug 2013 05:15:45 -0400 (EDT) Message-ID: <520B4A76.8050903@huawei.com> Date: Wed, 14 Aug 2013 17:14:30 +0800 From: Xishi Qiu MIME-Version: 1.0 Subject: Re: [PATCH] mm: skip the page buddy block instead of one page References: <520B0B75.4030708@huawei.com> <20130814085711.GK2296@suse.de> In-Reply-To: <20130814085711.GK2296@suse.de> Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Andrew Morton , riel@redhat.com, Minchan Kim , aquini@redhat.com, linux-mm@kvack.org, LKML On 2013/8/14 16:57, 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 > buddy allocator (per-cpu allocator would be ok except for refills). I expect > it would not be a good tradeoff to acquire the lock just to use page_order. > > Nak. > Oh, you are right, we must hold zone->lock first. Thanks, Xishi Qiu -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org