Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754076Ab0HBQEw (ORCPT ); Mon, 2 Aug 2010 12:04:52 -0400 Received: from e39.co.us.ibm.com ([32.97.110.160]:49114 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751178Ab0HBQEv (ORCPT ); Mon, 2 Aug 2010 12:04:51 -0400 Subject: Re: [RFC PATCH v8 00/16] Provide a zero-copy method on KVM virtio-net. From: Shirley Ma To: "Michael S. Tsirkin" Cc: xiaohui.xin@intel.com, netdev@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@elte.hu, davem@davemloft.net, herbert@gondor.hengli.com.au, jdike@linux.intel.com In-Reply-To: <20100801083113.GB16158@redhat.com> References: <1280402088-5849-1-git-send-email-xiaohui.xin@intel.com> <1280442682.9058.15.camel@localhost.localdomain> <20100801083113.GB16158@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 02 Aug 2010 09:04:35 -0700 Message-ID: <1280765075.22830.10.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 (2.28.3-1.fc12) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 749 Lines: 22 Hello Michael, On Sun, 2010-08-01 at 11:31 +0300, Michael S. Tsirkin wrote: > I think we should explore the idea for the driver to fall back on data > copy > for small message sizes. > The benefit of zero copy would then be CPU utilization on large > messages. Yes, we used to have 128 bytes for small copy in other driver. I saw Xiaohui's patch here is using 64 bytes. I think we need to compare the performance on different platform to decide what's the best for small message size. Thanks Shirley -- 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/