From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 8 Nov 2007 10:59:29 -0800 (PST) From: Christoph Lameter Subject: Re: [patch 07/23] SLUB: Add defrag_ratio field and sysfs support. In-Reply-To: <20071108150705.GD2591@skynet.ie> Message-ID: References: <20071107011130.382244340@sgi.com> <20071107011228.102370371@sgi.com> <20071108150705.GD2591@skynet.ie> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Mel Gorman Cc: akpm@linux-foundatin.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Thu, 8 Nov 2007, Mel Gorman wrote: > On (06/11/07 17:11), Christoph Lameter didst pronounce: > > The defrag_ratio is used to set the threshold at which defragmentation > > should be run on a slabcache. > > > > I'm thick, I would like to see a quick note here on what defragmentation > means. Also, this defrag_ratio seems to have a significantly different > meaning to the other defrag_ratio which isn't helping my poor head at > all. Yes that is why they have different names. The remote_node_defrag ratio controls the amount of remote allocs we do to reduce fragmentation. > "The defrag_ratio sets a threshold at which a slab will be vacated of all > it's objects and the pages freed during memory reclaim." Sortof. If a slab is beyond the threshold during reclaim then reclaim will attempt to free the remaining objects in the slab to reclaim the whole slab. -- 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