From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f54.google.com (mail-qg0-f54.google.com [209.85.192.54]) by kanga.kvack.org (Postfix) with ESMTP id 9E1986B0254 for ; Wed, 5 Aug 2015 04:02:41 -0400 (EDT) Received: by qgeu79 with SMTP id u79so24431967qge.1 for ; Wed, 05 Aug 2015 01:02:41 -0700 (PDT) Received: from szxga01-in.huawei.com (szxga01-in.huawei.com. [58.251.152.64]) by mx.google.com with ESMTPS id 33si4141212qgl.25.2015.08.05.01.02.36 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Wed, 05 Aug 2015 01:02:40 -0700 (PDT) Message-ID: <55C1C132.2010805@huawei.com> Date: Wed, 5 Aug 2015 15:54:26 +0800 From: Xishi Qiu MIME-Version: 1.0 Subject: Re: [PATCH] mm: add the block to the tail of the list in expand() References: <55BB4027.7080200@huawei.com> <55BC0392.2070205@intel.com> <55BECC85.7050206@huawei.com> <55BEE99E.8090901@intel.com> <55C011A6.1090003@huawei.com> <55C0CBC3.2000602@intel.com> In-Reply-To: <55C0CBC3.2000602@intel.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: Andrew Morton , Mel Gorman , Vlastimil Babka , Johannes Weiner , Michal Hocko , iamjoonsoo.kim@lge.com, alexander.h.duyck@redhat.com, sasha.levin@oracle.com, Linux MM , LKML On 2015/8/4 22:27, Dave Hansen wrote: > On 08/03/2015 06:13 PM, Xishi Qiu wrote: >> How did you do the experiment? > > I just stuck in some counters in expand() that looked to see whether the > list was empty or not when the page is added and then printed them out > occasionally. > Hi Dave, I add some debug code like this, but it doesn't trigger the dump_stack(). --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -834,6 +834,12 @@ static inline void expand(struct zone *zone, struct page *page, continue; } #endif + + if (!list_empty(&area->free_list[migratetype])) { + printk("expand(), the list is not empty\n"); + dump_stack(); + } + list_add(&page[size].lru, &area->free_list[migratetype]); area->nr_free++; set_page_order(&page[size], high); > It will be interesting to see the results both on a freshly-booted > system and one that's reached relatively steady-state and is moving > around a minimal number of pageblocks between the different types. > > In any case, the end result here needs to be some indication that the > patch either helps ease fragmentation or helps performance. > > . > -- 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