From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id 36DC76B0071 for ; Fri, 22 Oct 2010 12:32:41 -0400 (EDT) Date: Fri, 22 Oct 2010 11:32:37 -0500 (CDT) From: Christoph Lameter Subject: Re: shrinkers: Add node to indicate where to target shrinking In-Reply-To: <20101022155513.GA26790@infradead.org> Message-ID: References: <20101021235854.GD3270@amd> <20101022155513.GA26790@infradead.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Christoph Hellwig Cc: Nick Piggin , akpm@linux-foundation.org, Pekka Enberg , David Rientjes , linux-mm@kvack.org, Andi Kleen List-ID: On Fri, 22 Oct 2010, Christoph Hellwig wrote: > > I think making shrinking decision per-zone is fine. But do we need to > duplicate all the lru lists and infrastructure per-zone for that instead > of simply per-zone? Even with per-node lists we can easily skip over > items from the wrong zone. > > Given that we have up to 6 zones per node currently, and we would mostly > use one with a few fallbacks that seems like a lot of overkill. Zones can also cause asymmetry in reclaim if per zone reclaim is done. Look at the following zone setup of a Dell R910: grep "^Node" /proc/zoneinfo Node 0, zone DMA Node 0, zone DMA32 Node 0, zone Normal Node 1, zone Normal Node 2, zone Normal Node 3, zone Normal A reclaim that does per zone reclaim (but in reality reclaims all objects in a node (or worse as most shrinkers do today in the whole system) will put 3x the pressure on node 0. -- 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