From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <47CC822E.8040702@cs.helsinki.fi> Date: Tue, 04 Mar 2008 00:56:46 +0200 From: Pekka Enberg MIME-Version: 1.0 Subject: Re: [patch 7/8] slub: Make the order configurable for each slab cache References: <20080229044803.482012397@sgi.com> <20080229044820.044485187@sgi.com> <47C7BEA8.4040906@cs.helsinki.fi> <84144f020803010147y489b06fdx479ed0af931de08b@mail.gmail.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Mel Gorman , Matt Mackall , linux-mm@kvack.org List-ID: Christoph Lameter wrote: > On Sat, 1 Mar 2008, Pekka Enberg wrote: > >> I am not sure I understand what you mean here. For example, for a >> cache that requires minimum order of 1 to fit any objects (which >> doesn't happen now because of page allocator pass-through), the >> order_store() function can call calculate_sizes() with forced_order > > It does happen because the page allocator pass through is only possible > for kmalloc allocations. > >> set to zero after which the cache becomes useless. That deserves a >> code comment, I think. > > If the object does not fit into a page then calculate_sizes will violate > max_order (if necessary) in order to make sure that an allocation is > possible. Hmm, I seem to be missing something here. For page size of 4KB, object size of 8KB, and min_order of zero, when I write zero order to /sys/kernel/slab//order the kernel won't crash because...? Pekka -- 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