From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx203.postini.com [74.125.245.203]) by kanga.kvack.org (Postfix) with SMTP id C50056B0005 for ; Thu, 18 Apr 2013 11:02:56 -0400 (EDT) Date: Thu, 18 Apr 2013 08:02:02 -0700 From: Johannes Weiner Subject: Re: [PATCH 03/10] mm: vmscan: Flatten kswapd priority loop Message-ID: <20130418150202.GE2018@cmpxchg.org> References: <1365710278-6807-1-git-send-email-mgorman@suse.de> <1365710278-6807-4-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1365710278-6807-4-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Andrew Morton , Jiri Slaby , Valdis Kletnieks , Rik van Riel , Zlatko Calusic , dormando , Michal Hocko , Kamezawa Hiroyuki , Linux-MM , LKML On Thu, Apr 11, 2013 at 08:57:51PM +0100, Mel Gorman wrote: > kswapd stops raising the scanning priority when at least SWAP_CLUSTER_MAX > pages have been reclaimed or the pgdat is considered balanced. It then > rechecks if it needs to restart at DEF_PRIORITY and whether high-order > reclaim needs to be reset. This is not wrong per-se but it is confusing > to follow and forcing kswapd to stay at DEF_PRIORITY may require several > restarts before it has scanned enough pages to meet the high watermark even > at 100% efficiency. This patch irons out the logic a bit by controlling > when priority is raised and removing the "goto loop_again". > > This patch has kswapd raise the scanning priority until it is scanning > enough pages that it could meet the high watermark in one shrink of the > LRU lists if it is able to reclaim at 100% efficiency. It will not raise > the scanning prioirty higher unless it is failing to reclaim any pages. > > To avoid infinite looping for high-order allocation requests kswapd will > not reclaim for high-order allocations when it has reclaimed at least > twice the number of pages as the allocation request. > > Signed-off-by: Mel Gorman Acked-by: Johannes Weiner -- 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