From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 4DF846B004A for ; Wed, 1 Jun 2011 13:58:16 -0400 (EDT) Date: Wed, 1 Jun 2011 18:58:09 +0100 From: Mel Gorman Subject: Re: [PATCH] mm: compaction: Abort compaction if too many pages are isolated and caller is asynchronous Message-ID: <20110601175809.GB7306@suse.de> References: <20110530131300.GQ5044@csn.ul.ie> <20110530143109.GH19505@random.random> <20110530153748.GS5044@csn.ul.ie> <20110530165546.GC5118@suse.de> <20110530175334.GI19505@random.random> <20110531121620.GA3490@barrios-laptop> <20110531122437.GJ19505@random.random> <20110531133340.GB3490@barrios-laptop> <20110531141402.GK19505@random.random> <20110601005747.GC7019@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20110601005747.GC7019@csn.ul.ie> Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: Minchan Kim , akpm@linux-foundation.org, Ury Stankevich , KOSAKI Motohiro , linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@kernel.org On Wed, Jun 01, 2011 at 01:57:47AM +0100, Mel Gorman wrote: > On Tue, May 31, 2011 at 04:14:02PM +0200, Andrea Arcangeli wrote: > > On Tue, May 31, 2011 at 10:33:40PM +0900, Minchan Kim wrote: > > > I checked them before sending patch but I got failed to find strange things. :( > > > > My review also doesn't show other bugs in migrate_pages callers like > > that one. > > > > > Now I am checking the page's SwapBacked flag can be changed > > > between before and after of migrate_pages so accounting of NR_ISOLATED_XX can > > > make mistake. I am approaching the failure, too. Hmm. > > > > When I checked that, I noticed the ClearPageSwapBacked in swapcache if > > radix insertion fails, but that happens before adding the page in the > > LRU so it shouldn't have a chance to be isolated. > > > > After hammering three machines for several hours, I managed to trigger > this once on x86 !CONFIG_SMP CONFIG_PREEMPT HIGHMEM4G (so no PAE) > and caught the following trace. > Umm, HIGHMEM4G implies a two-level pagetable layout so where are things like _PAGE_BIT_SPLITTING being set when THP is enabled? -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org