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=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,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 2BFB5C10F0E for ; Fri, 12 Apr 2019 15:15:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF2392084D for ; Fri, 12 Apr 2019 15:15:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="w5KqEqEM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726765AbfDLPPL (ORCPT ); Fri, 12 Apr 2019 11:15:11 -0400 Received: from mail-pl1-f182.google.com ([209.85.214.182]:40023 "EHLO mail-pl1-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726755AbfDLPPL (ORCPT ); Fri, 12 Apr 2019 11:15:11 -0400 Received: by mail-pl1-f182.google.com with SMTP id b3so5283344plr.7 for ; Fri, 12 Apr 2019 08:15:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=3Ycgg4Afnb+vlRVtOUwu3IY3C4esXyrX1AS6M3ab8/0=; b=w5KqEqEMuxDAsrLWutx/vY9SSLmtQ5MyqTM3zsjy74zQA0di9CjO7bvlb0Yuk7Q9+P M/Qc4sk4zkE/CB4cjIknGd9O0TNmU/qvsskOg9662YckOs/auaXxd/+zvYIDEWqfK5Ky Nej9fBXu9mII7EXQGrTKjTZaYRlRguetsOUFmECEDNDOA0SXteWmwJTceS4sdzNT92w2 Su/sNvi+Y1u7lqrzwdZgsQqrnKzuPbJVMiazrCqAyJYS78LBAKUmPasEWJFi1/t9B7L5 6AZILoHTI0KEkB2RYNyUKDthJ4Yus74ADXhaqJ8jTNsLdbKUc+lFld50j3JHjFiGTfvS 9oIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=3Ycgg4Afnb+vlRVtOUwu3IY3C4esXyrX1AS6M3ab8/0=; b=LqSFYB01wyeL2QDu4TEaxilwPRQI39RugHdcCYrF862kfM1AuUdDKNUULtBYNv6VEw pSjVFQpw5mXSXLJSwydmRmiEz8QLML+pKT5ByhXHaYOXCmHMWb7R4nZOvjiT4EWERq6a 5/XSS5Pyt6OhtuGI2iKCeynhTJE7Z3BFIIMaf9nWeL4g1OSu+XB+BVlSvm6/UE/5738L t+jFzzYFWKWWs2mrwrGYAL5nhNqn7Pp02q7bcs/awM7P/q00B+KIiDkewSAmODPx91aG s4Gs3H+F/twAkf8tYApL1IAKUViirBrMhl130XNRkbpvv1d4YFRNE97g+XOCOlJqMDzH mFug== X-Gm-Message-State: APjAAAXek8e2u+dNcBRjcpEIwYYWLpmyCfdq90KfclaVhi8sF2QXpq68 kLoJ2SKJgAQSDRm7FVQwjU5bfexOoWiK8A== X-Google-Smtp-Source: APXvYqxJDkDGnRD0N6WlRijpAhV9VovGO1dtdK2NHaPcV60tMYgzdNb2k81vZMFgDtXK3Fw3rJ6Ing== X-Received: by 2002:a17:902:8c89:: with SMTP id t9mr58333519plo.265.1555082109947; Fri, 12 Apr 2019 08:15:09 -0700 (PDT) Received: from [192.168.1.121] (66.29.188.166.static.utbb.net. [66.29.188.166]) by smtp.gmail.com with ESMTPSA id p14sm46738111pfa.26.2019.04.12.08.15.08 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 12 Apr 2019 08:15:08 -0700 (PDT) Subject: Re: avoid calling nth_page in the block I/O path v2 To: Christoph Hellwig Cc: Ming Lei , linux-block@vger.kernel.org References: <20190411062331.27800-1-hch@lst.de> From: Jens Axboe Message-ID: <9a5a3a14-0438-2a31-661f-02fcb16dc767@kernel.dk> Date: Fri, 12 Apr 2019 09:15:06 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190411062331.27800-1-hch@lst.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 4/11/19 12:23 AM, Christoph Hellwig wrote: > Hi Jens, > > you complained about the overhead of calling nth_page in the multipage > bio_vec enabled I/O path a while ago. While I can't really reproduce > the numbers on my (slower) hardware we could avoid the nth_page calls > pretty easily with a few tweaks. Can you take a look at this series? > > Changes since v1: > - remove a spurious variable initialization Applied for 5.2, thanks. -- Jens Axboe