From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750986AbXAFReW (ORCPT ); Sat, 6 Jan 2007 12:34:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750892AbXAFReW (ORCPT ); Sat, 6 Jan 2007 12:34:22 -0500 Received: from p02c11o143.mxlogic.net ([208.65.145.66]:50616 "EHLO p02c11o143.mxlogic.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750782AbXAFReU (ORCPT ); Sat, 6 Jan 2007 12:34:20 -0500 Date: Sat, 6 Jan 2007 19:34:40 +0200 From: "Michael S. Tsirkin" To: Felix Marti Cc: Steve Wise , Roland Dreier , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, openib-general@openib.org Subject: Re: [PATCH v4 01/13] Linux RDMA Core Changes Message-ID: <20070106173439.GC26997@mellanox.co.il> Reply-To: "Michael S. Tsirkin" References: <8A71B368A89016469F72CD08050AD334F3BE50@maui.asicdesigners.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8A71B368A89016469F72CD08050AD334F3BE50@maui.asicdesigners.com> User-Agent: Mutt/1.5.11 X-OriginalArrivalTime: 06 Jan 2007 17:35:48.0252 (UTC) FILETIME=[1A40E5C0:01C731B9] X-TM-AS-Product-Ver: SMEX-7.0.0.1526-3.6.1039-14918.000 X-TM-AS-Result: No--7.003500-4.000000-31 X-Spam: [F=0.0100000000; S=0.010(2006120601)] X-MAIL-FROM: X-SOURCE-IP: [194.90.237.34] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > [Felix Marti] In addition, is arming the CQ really in the performance > path? - Don't apps poll the CQ as long as there are pending CQEs and > only arm the CQ for notification once there is nothing left to do? If > this is the case, it would mean that we waste a few cycles 'idle' > cycles. Applications such as IPoIB might queue up packets, then ARM the CQ, and only then they are processed by the upper layers in the stack. So arming the CQ is on hot datapath. -- MST