From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 14 May 2007 09:37:42 -0700 (PDT) From: Christoph Lameter Subject: Re: [PATCH 0/5] make slab gfp fair In-Reply-To: <1179159011.2942.16.camel@lappy> Message-ID: References: <20070514131904.440041502@chello.nl> <1179159011.2942.16.camel@lappy> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Thomas Graf , David Miller , Andrew Morton , Daniel Phillips , Pekka Enberg , Matt Mackall List-ID: On Mon, 14 May 2007, Peter Zijlstra wrote: > > Why does this have to handled by the slab allocators at all? If you have > > free pages in the page allocator then the slab allocators will be able to > > use that reserve. > > Yes, too freely. GFP flags are only ever checked when you allocate a new > page. Hence, if you have a low reaching alloc allocating a slab page; > subsequent non critical GFP_KERNEL allocs can fill up that slab. Hence > you would need to reserve a slab per object instead of the normal > packing. This is all about making one thread fail rather than another? Note that the allocations are a rather compex affair in the slab allocators. Per node and per cpu structures play a big role. -- 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