From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 12 Jun 2007 22:32:03 -0500 From: Matt Mackall Subject: Re: [PATCH] slob: poor man's NUMA, take 2. Message-ID: <20070613033203.GO11115@waste.org> References: <20070613031203.GB15009@linux-sh.org> <466F6351.9040503@yahoo.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <466F6351.9040503@yahoo.com.au> Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Paul Mundt , Christoph Lameter , Andrew Morton , linux-mm@kvack.org List-ID: On Wed, Jun 13, 2007 at 01:24:01PM +1000, Nick Piggin wrote: > Paul Mundt wrote: > >Here's an updated copy of the patch adding simple NUMA support to SLOB, > >against the current -mm version of SLOB this time. > > > >I've tried to address all of the comments on the initial version so far, > >but there's obviously still room for improvement. > > > >This approach is not terribly scalable in that we still end up using a > >global freelist (and a global spinlock!) across all nodes, making the > >partial free page lookup rather expensive. The next step after this will > >be moving towards split freelists with finer grained locking. > > I just think that this is not really a good intermediate step because > you only get NUMA awareness from the first allocation out of a page. I > guess that's an easy no-brainer for bigblock allocations, but for SLUB > proper, it seems not so good. > > For a lot of workloads you will have a steady state where allocation and > freeing rates match pretty well and there won't be much movement of pages > in and out of the allocator. In this case it will be back to random > allocations, won't it? Hmmm, probably. Perhaps we can have a single list (or ring, rather) with per-node insertion points. Then we can start node-local searches at the insertion points..? -- Mathematics is the supreme nostalgia of our time. -- 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