From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261685AbUL3SAf (ORCPT ); Thu, 30 Dec 2004 13:00:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261688AbUL3SAe (ORCPT ); Thu, 30 Dec 2004 13:00:34 -0500 Received: from one.firstfloor.org ([213.235.205.2]:43699 "EHLO one.firstfloor.org") by vger.kernel.org with ESMTP id S261685AbUL3SA2 (ORCPT ); Thu, 30 Dec 2004 13:00:28 -0500 To: Alan Cox Cc: netdev@oss.sgi.com, linux-kernel@vger.kernel.org Subject: Re: PATCH: kmalloc packet slab References: <1104156983.20944.25.camel@localhost.localdomain> From: Andi Kleen Date: Thu, 30 Dec 2004 19:00:25 +0100 In-Reply-To: <1104156983.20944.25.camel@localhost.localdomain> (Alan Cox's message of "Mon, 27 Dec 2004 14:16:23 +0000") Message-ID: User-Agent: Gnus/5.110002 (No Gnus v0.2) Emacs/21.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Alan Cox writes: > The networking world runs in 1514 byte packets pretty much all the time. > This adds a 1620 byte slab for such objects and is one of the internally > generated Red Hat patches we use on things like Fedora Core 3. Original: > Arjan van de Ven. Doesnt this clash a bit with yours and Arjans no-prisoners-taken quest to get rid of order>0 allocations? (4K stacks). I implemented this long ago (in 2.1 - bonus points if you still find the leftover hook), but then gave up on it. I realized that to use it you would need order>0 allocations. In a single 4K page only 2 1.5K slabs fit, but 2 2K slabs fit as well. And there is already a handy 2K slab that works perfect well. IMHO it is useless except for architectures with PAGE_SIZE>4K or if you fix the VM to handle order>0 allocations really well. If you want to add it for sparc64/ia64/alpha etc. I would do it with an ifdef at least. -Andi