From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 152626B0047 for ; Tue, 28 Sep 2010 10:08:27 -0400 (EDT) Date: Tue, 28 Sep 2010 09:08:46 -0500 (CDT) From: Christoph Lameter Subject: Re: zone state overhead In-Reply-To: <20100928135148.GM8187@csn.ul.ie> Message-ID: References: <20100928050801.GA29021@sli10-conroe.sh.intel.com> <20100928133059.GL8187@csn.ul.ie> <20100928135148.GM8187@csn.ul.ie> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Mel Gorman Cc: Shaohua Li , linux-mm@kvack.org List-ID: On Tue, 28 Sep 2010, Mel Gorman wrote: > On Tue, Sep 28, 2010 at 08:40:15AM -0500, Christoph Lameter wrote: > > On Tue, 28 Sep 2010, Mel Gorman wrote: > > > > > Which of these is better or is there an alternative suggestion on how > > > this livelock can be avoided? > > > > We need to run some experiments to see what is worse. Lets start by > > cutting both the stats threshold and the drift thing in half? > > > > Ok, I have no problem with that although again, I'm really not in the position > to roll patches for it right now. I don't want to get side-tracked. Ok the stat threshold determines the per_cpu_drift_mark. So changing the threshold should do the trick. Try this: --- mm/vmstat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-2.6/mm/vmstat.c =================================================================== --- linux-2.6.orig/mm/vmstat.c 2010-09-28 09:04:48.000000000 -0500 +++ linux-2.6/mm/vmstat.c 2010-09-28 09:05:16.000000000 -0500 @@ -118,7 +118,7 @@ static int calculate_threshold(struct zo mem = zone->present_pages >> (27 - PAGE_SHIFT); - threshold = 2 * fls(num_online_cpus()) * (1 + fls(mem)); + threshold = fls(num_online_cpus()) * (1 + fls(mem)); /* * Maximum threshold is 125 -- 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