From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758495Ab0J1PYt (ORCPT ); Thu, 28 Oct 2010 11:24:49 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.141]:40128 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756307Ab0J1PYm (ORCPT ); Thu, 28 Oct 2010 11:24:42 -0400 Subject: Re: [RFC PATCH 1/1] vhost: TX used buffer guest signal accumulation From: Shirley Ma To: "Michael S. Tsirkin" Cc: David Miller , netdev@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20101028052021.GD5599@redhat.com> References: <1288216693.17571.38.camel@localhost.localdomain> <1288240804.14342.1.camel@localhost.localdomain> <20101028052021.GD5599@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 28 Oct 2010 08:24:37 -0700 Message-ID: <1288279477.11251.5.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 On Thu, 2010-10-28 at 07:20 +0200, Michael S. Tsirkin wrote: > My concern is this can delay signalling for unlimited time. > Could you pls test this with guests that do not have > 2b5bbe3b8bee8b38bdc27dd9c0270829b6eb7eeb > b0c39dbdc204006ef3558a66716ff09797619778 > that is 2.6.31 and older? I will test it out. > This seems to be slighltly out of spec, even though > for TX, signals are less important. > Two ideas: > 1. How about writing out used, just delaying the signal? > This way we don't have to queue separately. > 2. How about flushing out queued stuff before we exit > the handle_tx loop? That would address most of > the spec issue. I will modify the patch to test out the performance for both 1 & 2 approaches. Thanks Shirley