From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757177AbcB1JJE (ORCPT ); Sun, 28 Feb 2016 04:09:04 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:43282 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756983AbcB1JI6 (ORCPT ); Sun, 28 Feb 2016 04:08:58 -0500 Date: Sun, 28 Feb 2016 01:08:58 -0800 From: Christoph Hellwig To: Santosh Shilimkar Cc: netdev@vger.kernel.org, davem@davemloft.net, linux-kernel@vger.kernel.org Subject: Re: [net-next][PATCH v2 11/13] RDS: IB: add Fastreg MR (FRMR) detection support Message-ID: <20160228090858.GB6671@infradead.org> References: <1456625990-4739-1-git-send-email-santosh.shilimkar@oracle.com> <1456625990-4739-12-git-send-email-santosh.shilimkar@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1456625990-4739-12-git-send-email-santosh.shilimkar@oracle.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 27, 2016 at 06:19:48PM -0800, Santosh Shilimkar wrote: > Discovere Fast Memmory Registration support using IB device > IB_DEVICE_MEM_MGT_EXTENSIONS. Certain HCA might support just FRMR > or FMR or both FMR and FRWR. In case both mr type are supported, > default FMR is used. > > Default MR is still kept as FMR against what everyone else > is following. Default will be changed to FRMR once the > RDS performance with FRMR is comparable with FMR. The > work is in progress for the same. > > Signed-off-by: Santosh Shilimkar > Signed-off-by: Santosh Shilimkar > --- > v2: Dropped the module parameter as suggested by David Miller This means we only use the safer method if the HCA doesn't support the other one. All other RDMA ULP that support both methods have a module_param so the veto from Dave is a bit unfortunate. Anyway, let's get the code in for now and figure out what to use later. Just curious: where / how do you see worse peformance using FRs?