Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756795Ab2JCW1r (ORCPT ); Wed, 3 Oct 2012 18:27:47 -0400 Received: from ozlabs.org ([203.10.76.45]:33827 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756707Ab2JCW1p (ORCPT ); Wed, 3 Oct 2012 18:27:45 -0400 From: Rusty Russell To: "Michael S. Tsirkin" , Thomas Lendacky Cc: Sasha Levin , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, avi@redhat.com, kvm@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH 0/3] virtio-net: inline header support In-Reply-To: <87vces2gxq.fsf@rustcorp.com.au> References: <87vces2gxq.fsf@rustcorp.com.au> User-Agent: Notmuch/0.13.2 (http://notmuchmail.org) Emacs/23.3.1 (i686-pc-linux-gnu) Date: Wed, 03 Oct 2012 16:40:06 +0930 Message-ID: <87sj9w2fqp.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 985 Lines: 30 Rusty Russell writes: > "Michael S. Tsirkin" writes: > >> Thinking about Sasha's patches, we can reduce ring usage >> for virtio net small packets dramatically if we put >> virtio net header inline with the data. >> This can be done for free in case guest net stack allocated >> extra head room for the packet, and I don't see >> why would this have any downsides. > > I've been wanting to do this for the longest time... but... > >> Even though with my recent patches qemu >> no longer requires header to be the first s/g element, Breaks for me; see why I hate bug features? Now we'd need another one... qemu-system-i386: virtio: trying to map MMIO memory Please try my patch. Cheers, Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/