From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx189.postini.com [74.125.245.189]) by kanga.kvack.org (Postfix) with SMTP id 872B46B0087 for ; Wed, 14 Aug 2013 04:57:17 -0400 (EDT) Date: Wed, 14 Aug 2013 09:57:11 +0100 From: Mel Gorman Subject: Re: [PATCH] mm: skip the page buddy block instead of one page Message-ID: <20130814085711.GK2296@suse.de> References: <520B0B75.4030708@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <520B0B75.4030708@huawei.com> Sender: owner-linux-mm@kvack.org List-ID: To: Xishi Qiu Cc: Andrew Morton , riel@redhat.com, Minchan Kim , aquini@redhat.com, linux-mm@kvack.org, LKML 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. -- Mel Gorman SUSE Labs -- 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