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=-4.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=unavailable 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 32484C43441 for ; Fri, 16 Nov 2018 02:18:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EADE82145D for ; Fri, 16 Nov 2018 02:18:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=osandov-com.20150623.gappssmtp.com header.i=@osandov-com.20150623.gappssmtp.com header.b="mxj5a+9W" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EADE82145D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=osandov.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-btrfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389346AbeKPM2u (ORCPT ); Fri, 16 Nov 2018 07:28:50 -0500 Received: from mail-pg1-f195.google.com ([209.85.215.195]:44034 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727061AbeKPM2n (ORCPT ); Fri, 16 Nov 2018 07:28:43 -0500 Received: by mail-pg1-f195.google.com with SMTP id t13so1221728pgr.11 for ; Thu, 15 Nov 2018 18:18:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=osandov-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=uWxOI7EW+B6BaLJ4pF1Ucb4JKvaIuWDE5mYJ2nvblqE=; b=mxj5a+9WhaUzzn6ENIPyyJMDBjBRDUGhUl2p38GDhnPH+yLz97xJGMlhaOjc+x0c96 SZP6XEZfRQZo5jsFCwlLfiDojuqLbpzRHVh52QfLDd9K55bag+4IyroxO1cq3SrkGVbp wpNoT55+M98lKeG/wuihGyrjfR1RhTKeyN+f8S/X2Ktx1Q0eqUJz5rqTgM/A4Pbv7duR LB28WnNvGsapqmb77uTNrgtK4BqM45hHGbHpDKezmNiNdQB2AJf/s09zpqWwyhfB/ShX C70fPi4L089v3cKjZaCZGf6oYE4VzreeOOSc997WA0dDu7InSYJwxQSzz1KHpuUeoL4Q F6Jw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=uWxOI7EW+B6BaLJ4pF1Ucb4JKvaIuWDE5mYJ2nvblqE=; b=fd/HlTqliZmopD5D3PdY4q1plR4di6e+AE3IFNvX0XRne4sFyyVo7cra4LEFhpFdKy Q9RHR+CPwzD1rTu3dUXAj0aKnnDZ9Ucz/x+qlioTXxi0DwimftCP93ejW+5x9khWs4ib /MfVxR1Ha6IDdWB1cjYf8oNVYeNU4nJS/miJNPEvdnmP/Qo7UotbL62Olk7FD74NzvUV Egb7+pN3VyeI+2XG2tlofn8ZgChkWdR9jlbUJLOpgTSAFcCrD/cAunUwFK+OsUK2GndU CdIW6zGd6hPVwC6ikbO0+vi4bGvg3p7gDtF8nu7ft6oVnKCTk4QcCdqdyd+4J6XO+m6U 1W0Q== X-Gm-Message-State: AGRZ1gKZ2p+ingr1/tUA73xb9zfbMBqxgmcxlv2yu/TXwB75BQA7P6xW Rvv8jjppZhK/nPINIawOtggDwg== X-Google-Smtp-Source: AJdET5cfhaHk05TqW2Jq6nTxtIdo0ficfDaKFmLY+f8LDNaSqXZd501bp6MC6dyRxNdzTO6b9nJlNw== X-Received: by 2002:a63:101d:: with SMTP id f29mr8219269pgl.38.1542334693471; Thu, 15 Nov 2018 18:18:13 -0800 (PST) Received: from vader ([64.114.255.97]) by smtp.gmail.com with ESMTPSA id v15sm8249986pfn.94.2018.11.15.18.18.12 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 15 Nov 2018 18:18:12 -0800 (PST) Date: Thu, 15 Nov 2018 18:18:11 -0800 From: Omar Sandoval To: Ming Lei Cc: Jens Axboe , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dave Chinner , Kent Overstreet , Mike Snitzer , dm-devel@redhat.com, Alexander Viro , linux-fsdevel@vger.kernel.org, Shaohua Li , linux-raid@vger.kernel.org, linux-erofs@lists.ozlabs.org, David Sterba , linux-btrfs@vger.kernel.org, "Darrick J . Wong" , linux-xfs@vger.kernel.org, Gao Xiang , Christoph Hellwig , Theodore Ts'o , linux-ext4@vger.kernel.org, Coly Li , linux-bcache@vger.kernel.org, Boaz Harrosh , Bob Peterson , cluster-devel@redhat.com Subject: Re: [PATCH V10 18/19] block: kill QUEUE_FLAG_NO_SG_MERGE Message-ID: <20181116021811.GM23828@vader> References: <20181115085306.9910-1-ming.lei@redhat.com> <20181115085306.9910-19-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181115085306.9910-19-ming.lei@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thu, Nov 15, 2018 at 04:53:05PM +0800, Ming Lei wrote: > Since bdced438acd83ad83a6c ("block: setup bi_phys_segments after splitting"), > physical segment number is mainly figured out in blk_queue_split() for > fast path, and the flag of BIO_SEG_VALID is set there too. > > Now only blk_recount_segments() and blk_recalc_rq_segments() use this > flag. > > Basically blk_recount_segments() is bypassed in fast path given BIO_SEG_VALID > is set in blk_queue_split(). > > For another user of blk_recalc_rq_segments(): > > - run in partial completion branch of blk_update_request, which is an unusual case > > - run in blk_cloned_rq_check_limits(), still not a big problem if the flag is killed > since dm-rq is the only user. > > Multi-page bvec is enabled now, QUEUE_FLAG_NO_SG_MERGE doesn't make sense any more. This commit message wasn't very clear. Is it the case that QUEUE_FLAG_NO_SG_MERGE is no longer set by any drivers?