From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932632AbcFGNOQ (ORCPT ); Tue, 7 Jun 2016 09:14:16 -0400 Received: from mail-wm0-f49.google.com ([74.125.82.49]:35987 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932308AbcFGNOO (ORCPT ); Tue, 7 Jun 2016 09:14:14 -0400 Subject: Re: [PATCH v2] IB/core: remove dead code To: Christoph Hellwig , Sagi Grimberg References: <1465247706-4418-1-git-send-email-sudipm.mukherjee@gmail.com> <5756C0E0.7090303@lightbits.io> <20160607124259.GA3906@infradead.org> Cc: Sudip Mukherjee , Doug Ledford , Sean Hefty , Hal Rosenstock , linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, leon@kernel.org, Max Gurtovoy From: Sagi Grimberg Message-ID: <5756C8A2.5060305@lightbits.io> Date: Tue, 7 Jun 2016 16:14:10 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: <20160607124259.GA3906@infradead.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> Actually it looks like the data-integrity insert/strip operation >> (where protection sg list does not exist) is broken. >> >> It looks that the protection scatterlist should be done only if >> prot_sg_count was provided... >> >> I don't have access to mlx5 devices at the moment (still waiting >> to get some...) Hey Christoph, > I've reported the brokenness in the existing iSER code when I started > working on signature MR support in the generic API. As no one helped > managed to figure out the issue or how it should operate I clone the > existing semantics, even given I knew they are broken. There are two modes for the insert/strip operation, one is with PI on memory and without on the wire (which is useful when having a target working against legacy initiators), and one is with PI on the wire but not in memory. You reported that the latter was broken (the less useful case) and my understanding is that it was a result of the target<->isert interaction. The last time I used the first mode it worked fine. I'll try to get my hands on some mlx5 devices soon and have a look into this. I still want to change the API so it will hide all this noise from the consumer but I need to find some spare cycles for it. In the meantime, CC'ing Max from Mellanox and maybe he can check if PI insert/strip are still alive. Cheers, Sagi.