From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx161.postini.com [74.125.245.161]) by kanga.kvack.org (Postfix) with SMTP id 2DFF06B00E3 for ; Wed, 7 Aug 2013 11:13:08 -0400 (EDT) Date: Wed, 7 Aug 2013 16:13:03 +0100 From: Mel Gorman Subject: Re: [PATCH 1/9] mm: zone_reclaim: remove ZONE_RECLAIM_LOCKED Message-ID: <20130807151303.GR2296@suse.de> References: <1375459596-30061-1-git-send-email-aarcange@redhat.com> <1375459596-30061-2-git-send-email-aarcange@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1375459596-30061-2-git-send-email-aarcange@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: linux-mm@kvack.org, Johannes Weiner , Rik van Riel , Hugh Dickins , Richard Davies , Shaohua Li , Rafael Aquini , Andrew Morton , Hush Bensen On Fri, Aug 02, 2013 at 06:06:28PM +0200, Andrea Arcangeli wrote: > Zone reclaim locked breaks zone_reclaim_mode=1. If more than one > thread allocates memory at the same time, it forces a premature > allocation into remote NUMA nodes even when there's plenty of clean > cache to reclaim in the local nodes. > > Signed-off-by: Andrea Arcangeli > Reviewed-by: Rik van Riel > Acked-by: Rafael Aquini > Acked-by: KOSAKI Motohiro I would have preferred if the changelog included the history of why this exists at all (prevents excessive reclaim from parallel allocation requests) and why it should not currently be a problem (SWAP_CLUSTER_MAX should be strictly obeyed limiting the excessive reclaim to SWAP_CLUSTER_MAX * nr_parallel_requests). Hopefully we'll remember to connect any bugs about excessive reclaim + zone_reclaim to this patch :) Acked-by: Mel Gorman -- 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