From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx149.postini.com [74.125.245.149]) by kanga.kvack.org (Postfix) with SMTP id CCAE36B005A for ; Thu, 6 Sep 2012 08:17:29 -0400 (EDT) Date: Thu, 6 Sep 2012 13:17:25 +0100 From: Mel Gorman Subject: Re: [patch 1/2]compaction: check migrated page number Message-ID: <20120906121725.GQ11266@suse.de> References: <20120906104404.GA12718@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20120906104404.GA12718@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: Shaohua Li Cc: linux-mm@kvack.org, akpm@linux-foundation.org, aarcange@redhat.com On Thu, Sep 06, 2012 at 06:44:04PM +0800, Shaohua Li wrote: > > isolate_migratepages_range() might isolate none pages, for example, when > zone->lru_lock is contended and compaction is async. In this case, we should > abort compaction, otherwise, compact_zone will run a useless loop and make > zone->lru_lock is even contended. > It might also isolate no pages because the range was 100% allocated and there were no free pages to isolate. This is perfectly normal and I suspect this patch effectively disables compaction. What problem did you observe that this patch is aimed at? -- 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