From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: skb_shared_info() Date: Mon, 14 Aug 2006 10:18:05 +0200 Message-ID: <200608141018.05649.ak@suse.de> References: <20060808.163915.03600382.davem@davemloft.net> <200608140945.53713.ak@suse.de> <20060814075045.GA1437@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: David Miller , netdev@vger.kernel.org, johnpol@2ka.mipt.ru Return-path: Received: from mx1.suse.de ([195.135.220.2]:38548 "EHLO mx1.suse.de") by vger.kernel.org with ESMTP id S1751931AbWHNISR (ORCPT ); Mon, 14 Aug 2006 04:18:17 -0400 To: Herbert Xu In-Reply-To: <20060814075045.GA1437@gondor.apana.org.au> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Monday 14 August 2006 09:50, Herbert Xu wrote: > On Mon, Aug 14, 2006 at 09:45:53AM +0200, Andi Kleen wrote: > > > > Even for 1.5k MTU? (which is still the most common case after all) > > Ideally they would stay in kmalloc memory. Could you explain the cache > colouring problem for 1500-byte packets? kmalloc rounds the 1.5k up to 2k and with that exactly two objects fit into a 4k page. With that slab doesn't have any space left to do cache coloring. -Andi