From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 14 Feb 2008 11:04:52 -0800 (PST) From: Christoph Lameter Subject: Re: [patch 4/5] slub: Use __GFP_MOVABLE for slabs of HPAGE_SIZE In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Pekka Enberg Cc: "linux-mm@kvack.org" List-ID: On Thu, 14 Feb 2008, Pekka Enberg wrote: > > This will make a system that was booted with > > > > slub_min_order = 9 > > > > not have any reclaimable slab allocations anymore. All slab allocations > > will be of type MOVABLE (although they are not movable like huge pages > > are also not movable). This means that we only have MOVABLE and > > UNMOVABLE sections of memory which reduces the types of sections > > and therefore the danger of fragmenting memory. > > Why does slub_min_order=9 matter? I suppose this is fixing some other > real bug? Because some people run slub with huge page allocations. It makes a lot of sense on systems that have more than 4 - 8G of RAM per cpu. The 2M pages for 100 slab caches (usually we have only 70) take 200M which is just a small fraction of the memory for one processor. -- 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