From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 23 May 2007 14:35:47 -0500 From: Matt Mackall Subject: Re: [patch 1/3] slob: rework freelist handling Message-ID: <20070523193547.GE11115@waste.org> References: <20070523050333.GB29045@wotan.suse.de> <20070523051152.GC29045@wotan.suse.de> <20070523052206.GD29045@wotan.suse.de> <20070523061702.GA9449@wotan.suse.de> <20070523074636.GA10070@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Nick Piggin , Andrew Morton , Linux Memory Management List List-ID: On Wed, May 23, 2007 at 10:07:33AM -0700, Christoph Lameter wrote: > On Wed, 23 May 2007, Nick Piggin wrote: > > > Oh, and just out of interest, SLOB before my patches winds up with > > 1068K free, so it is good to know the patches were able to save a bit > > on this setup. > > Ahhh.. Its you who did the evil deed. By copying SLUB ideas SLOB became > better than SLUB. Uh, what? SLOB's memory usage was already better. Quoting Nick: > After booting and mounting /proc, SLOB has 1140K free, SLUB has 748K > free. So that's: 748K SLUB 1068K SLOB (old SLOB saves 320K) 1140K SLOB++ (Nick's improvements save an additional 72K for 392K total) (It'd be nice to have a SLAB number in there for completeness.) Nick's patches also make SLOB reasonably performant on larger machines (and can be a bit faster with a little tweaking). But it'll never be as fast as SLAB or SLUB - it has to walk lists. Similarly, I think it's basically impossible for a SLAB-like system that segregates objects of different sizes onto different pages to compete with a linked-list allocator on size. Especially now that Nick's reduced the kmalloc overhead to 2 bytes! So as long as there are machines where 100K or so makes a difference, there'll be a use for a SLOB-like allocator. -- 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