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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 E57CBC43387 for ; Sun, 23 Dec 2018 12:24:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD6452184D for ; Sun, 23 Dec 2018 12:24:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728181AbeLWMY3 (ORCPT ); Sun, 23 Dec 2018 07:24:29 -0500 Received: from mail-wm1-f67.google.com ([209.85.128.67]:50882 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725868AbeLWMY3 (ORCPT ); Sun, 23 Dec 2018 07:24:29 -0500 Received: by mail-wm1-f67.google.com with SMTP id n190so9239283wmd.0; Sun, 23 Dec 2018 04:24:28 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=IRVDC9MlYo+zGnerOqLUxppaH+DMuyi+9dgYiggvnjk=; b=QMpchS5pZvidheC5OB8q4rbKWHTLZYTOw/neMJEGsG1YEBOlFZzbX/pmH8kjSmUfVP uGvWLErPHfS2KkXmhDgYGahPXgVnwf149AAnTbflx67vbwAsVd91l6KQDLTKV1pzF9Rh CITBjHB8E86EMMPJPxcKK8pjc1+eeA+0h66NYCgGiC5ZDtbeQtpNX6I+Q4gZgWleKrQv 60cK0JEuDJMdGodHE/rzFZMmHgFPojjxe0f53qLI4dtuLvskqAdmtsZMll5Kz39jDfth JnqoOJXyxg2cbDvSdKZq8juPlQJWehruZeebQodrgROQBSWFsBpnuWeYtACiTuu6TrAp E/xQ== X-Gm-Message-State: AA+aEWZD83zx0D5z3r0Bymc30hq7yWedAgdokKiutcjk1d4ELwmWJCqb h3PdhqFY15wCdVJdMNpgjAPGBUkW X-Google-Smtp-Source: ALg8bN4FAT5pO8Jdo1DkP02fzPknXBrA26uA1ni2n7fLjNxtdcfDQXpxtv8qZlmMf5109vPSc6yZnA== X-Received: by 2002:a1c:16c5:: with SMTP id 188mr9500472wmw.69.1545567472204; Sun, 23 Dec 2018 04:17:52 -0800 (PST) Received: from [10.0.0.5] ([207.232.55.62]) by smtp.gmail.com with ESMTPSA id k135sm28258413wmd.42.2018.12.23.04.17.50 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 23 Dec 2018 04:17:51 -0800 (PST) Subject: Re: remove exofs, the T10 OSD code and block/scsi bidi support V3 To: Christoph Hellwig References: <20181111133211.13926-1-hch@lst.de> <4f4b6aff-6726-c500-e3e4-f8b73d641851@electrozaur.com> <20181219144347.GB23410@lst.de> Cc: axboe@kernel.dk, martin.petersen@oracle.com, Johannes Thumshirn , Benjamin Block , linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org From: Boaz Harrosh Message-ID: Date: Sun, 23 Dec 2018 14:17:49 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20181219144347.GB23410@lst.de> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 19/12/18 16:43, Christoph Hellwig wrote: > On Mon, Nov 26, 2018 at 07:11:10PM +0200, Boaz Harrosh wrote: >> On 11/11/18 15:32, Christoph Hellwig wrote: >>> The only real user of the T10 OSD protocol, the pNFS object layout >>> driver never went to the point of having shipping products, and we >>> removed it 1.5 years ago. Exofs is just a simple example without >>> real life users. >>> >> >> You have failed to say what is your motivation for this patchset? What >> is it you are trying to fix/improve. > > Drop basically unused support, which allows us to > > 1) reduce the size of every kernel with block layer support, and > even more for every kernel with scsi support Do you have numbers? its mainly code-segment so I don't think you will see any real life measurable difference. > 2) reduce the size of the critical struct request structure by > 128 bits, thus reducing the memory used by every blk-mq driver > significantly, never mind the cache effects 128 bits? I see the "struct request *next_rq;" is there another one? It could share space with elv; && flush; Do you want a patch? > 3) stop having the maintainance overhead for this code in the > block layer, which has been rather painful at times > I hear you man. Life is pain. But is it really such an overhead? I mean it is already implemented. What else is there to do? Please please show me? (Sorry for being slow) Jai Maa Boaz