From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id E42436B004F for ; Fri, 23 Oct 2009 09:39:10 -0400 (EDT) Date: Fri, 23 Oct 2009 14:39:08 +0100 From: Mel Gorman Subject: Re: [PATCH 4/5] page allocator: Pre-emptively wake kswapd when high-order watermarks are hit Message-ID: <20091023133908.GX11778@csn.ul.ie> References: <1256221356-26049-1-git-send-email-mel@csn.ul.ie> <1256221356-26049-5-git-send-email-mel@csn.ul.ie> <20091023091334.GV11778@csn.ul.ie> <20091023112512.GW11778@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org To: Tobias Oetiker Cc: David Rientjes , Frans Pop , Jiri Kosina , Sven Geggus , Karol Lewandowski , "Rafael J. Wysocki" , David Miller , Reinette Chatre , Kalle Valo , KOSAKI Motohiro , Mohamed Abbas , Jens Axboe , "John W. Linville" , Pekka Enberg , Bartlomiej Zolnierkiewicz , Greg Kroah-Hartman , Stephan von Krawczynski , Kernel Testers List , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "linux-mm@kvack.org" List-ID: On Fri, Oct 23, 2009 at 01:31:10PM +0200, Tobias Oetiker wrote: > Mel, > > Today Mel Gorman wrote: > > > On Fri, Oct 23, 2009 at 02:36:53AM -0700, David Rientjes wrote: > > > On Fri, 23 Oct 2009, Mel Gorman wrote: > > > > > > > > Hmm, is this really supposed to be added to __alloc_pages_high_priority()? > > > > > By the patch description I was expecting kswapd to be woken up > > > > > preemptively whenever the preferred zone is below ALLOC_WMARK_LOW and > > > > > we're known to have just allocated at a higher order, not just when > > > > > current was oom killed (when we should already be freeing a _lot_ of > > > > > memory soon) or is doing a higher order allocation during direct reclaim. > > > > > > > > > > > > > It was a somewhat arbitrary choice to have it trigger in the event high > > > > priority allocations were happening frequently. > > > > > > > > > > I don't quite understand, users of PF_MEMALLOC shouldn't be doing these > > > higher order allocations and if ALLOC_NO_WATERMARKS is by way of the oom > > > killer, we should be freeing a substantial amount of memory imminently > > > when it exits that waking up kswapd would be irrelevant. > > > > > > > I agree. I think it's highly unlikely this patch will make any > > difference but I wanted to eliminate it as a possibility. Patch 3 and 4 > > were previously one patch that were tested together. > > hi hi ... I have tested '3 only' this morning, and the allocation > problems started again ... so for me 3 alone does not work while > 3+4 does. > Hi, What was the outcome of 1+2? -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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