From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750821AbXACOZt (ORCPT ); Wed, 3 Jan 2007 09:25:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750819AbXACOZt (ORCPT ); Wed, 3 Jan 2007 09:25:49 -0500 Received: from rrcs-24-153-217-226.sw.biz.rr.com ([24.153.217.226]:43423 "EHLO smtp.opengridcomputing.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750818AbXACOZs (ORCPT ); Wed, 3 Jan 2007 09:25:48 -0500 Subject: Re: [PATCH v4 01/13] Linux RDMA Core Changes From: Steve Wise To: "Michael S. Tsirkin" Cc: rdreier@cisco.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, openib-general@openib.org In-Reply-To: <20061224084925.GD15106@mellanox.co.il> References: <20061214135233.21159.78613.stgit@dell3.ogc.int> <20061214135303.21159.61880.stgit@dell3.ogc.int> <20061224084925.GD15106@mellanox.co.il> Content-Type: text/plain Date: Wed, 03 Jan 2007 08:25:48 -0600 Message-Id: <1167834348.4187.3.camel@stevo-desktop> Mime-Version: 1.0 X-Mailer: Evolution 2.4.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > @@ -1373,7 +1374,7 @@ int ib_peek_cq(struct ib_cq *cq, int wc_ > > static inline int ib_req_notify_cq(struct ib_cq *cq, > > enum ib_cq_notify cq_notify) > > { > > - return cq->device->req_notify_cq(cq, cq_notify); > > + return cq->device->req_notify_cq(cq, cq_notify, NULL); > > } > > > > /** > > Can't say I like this adding overhead in data path operations (and note this > can't be optimized out). And kernel consumers work without passing it in, so it > hurts kernel code even for Chelsio. Granted, the cost is small here, but these > things do tend to add up. > > It seems all Chelsio needs is to pass in a consumer index - so, how about a new > entry point? Something like void set_cq_udata(struct ib_cq *cq, struct ib_udata *udata)? > Adding a new entry point would hurt chelsio's user mode performance if if then requires 2 kernel transitions to rearm the cq. Passing in user data is sort of SOP for these sorts of verbs. How much does passing one more param cost for kernel users?