From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 397B6C3A5A7 for ; Wed, 4 Sep 2019 12:49:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 190A421883 for ; Wed, 4 Sep 2019 12:49:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729398AbfIDMty (ORCPT ); Wed, 4 Sep 2019 08:49:54 -0400 Received: from verein.lst.de ([213.95.11.211]:39028 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727675AbfIDMty (ORCPT ); Wed, 4 Sep 2019 08:49:54 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 14C1A227A8A; Wed, 4 Sep 2019 14:49:50 +0200 (CEST) Date: Wed, 4 Sep 2019 14:49:49 +0200 From: Christoph Hellwig To: Max Gurtovoy Cc: Christoph Hellwig , Jens Axboe , Sagi Grimberg , linux-block@vger.kernel.org, martin.petersen@oracle.com, linux-nvme@lists.infradead.org, keith.busch@intel.com, shlomin@mellanox.com, israelr@mellanox.com Subject: Re: [PATCH 1/4] block: centrelize PI remapping logic to the block layer Message-ID: <20190904124949.GA17285@lst.de> References: <1567523655-23989-1-git-send-email-maxg@mellanox.com> <8df57b71-9404-904d-7abd-587942814039@grimberg.me> <20190904054956.GA10553@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Sep 04, 2019 at 11:32:04AM +0300, Max Gurtovoy wrote: > > On 9/4/2019 8:49 AM, Christoph Hellwig wrote: >> On Tue, Sep 03, 2019 at 01:21:59PM -0600, Jens Axboe wrote: >>> On 9/3/19 1:11 PM, Sagi Grimberg wrote: >>>>> + if (blk_integrity_rq(req) && req_op(req) == REQ_OP_READ && >>>>> + error == BLK_STS_OK) >>>>> + t10_pi_complete(req, >>>>> + nr_bytes / queue_logical_block_size(req->q)); >>>>> + >>>> div in this path? better to use >> ilog2(block_size). >>>> >>>> Also, would be better to have a wrapper in place like: >>>> >>>> static inline unsigned short blk_integrity_interval(struct request *rq) >>>> { >>>> return queue_logical_block_size(rq->q); >>>> } >>> If it's a hot path thing that matters, I'd strongly suggest to add >>> a queue block size shift instead. >> Make that a protection_interval_shift, please. While that currently >> is the same as the logical block size the concepts are a little >> different, and that makes it clear. Except for that this patch looks >> very nice to me, it is great to avoid having drivers to deal with the >> PI remapping. > > Christoph, > > I was thinking about the following addition to the code (combination of all > the suggestions): I'll defer to Martin, but I think we still need the integrity_interval naming in some form. static inline unsigned short queue_logical_block_shift(struct request_queue *q) > +{ > +       unsigned short retval = 9; > + > +       if (q && q->limits.logical_block_shift) > +               retval = q->limits.logical_block_shift; > + > +       return retval; I don't think a NULL queue makes any sense here. And I'd rather ensure the field is always set rather than adding a conditional here. And btw, centrelize in the Subject should be centralize.