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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9EA00C433F5 for ; Mon, 18 Oct 2021 17:53:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 847856115B for ; Mon, 18 Oct 2021 17:53:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232650AbhJRRzX (ORCPT ); Mon, 18 Oct 2021 13:55:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229836AbhJRRzW (ORCPT ); Mon, 18 Oct 2021 13:55:22 -0400 Received: from mail-io1-xd2a.google.com (mail-io1-xd2a.google.com [IPv6:2607:f8b0:4864:20::d2a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C2C6C06161C for ; Mon, 18 Oct 2021 10:53:11 -0700 (PDT) Received: by mail-io1-xd2a.google.com with SMTP id m20so17240834iol.4 for ; Mon, 18 Oct 2021 10:53:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=YH4oGe9dRfdZQ1d4CvnTMZ1r7HRf2QBAQWpHy9E3Wng=; b=UdB/aADcuFPlPcZ5zloyGSC8r8sjGP46bdFZgOczbw//2VtX+qD5PI/hTVyCm/RwVy FXAjDscH1TQ3fsg0fSzaSQe7AynSLix9FEl76DQK4y8MTjp/aJVzkmTFFG7c2xS8iXPi s+lRVm4eViQimOGv1xw+YUEHZjc66LhnruY2OKJU4kNG1W3nUI3yYhopF97varulsEhH lrAHcDhmWx+Ldz3ca7hK3R16UzzOUjcC//cwEEUu4EBzTbKGlwl++3WbIOKHwppSidbZ J2GwRHTpqmvpQIvUpXH1LIhuUZWDULALzfc74tUrBZWM1yZdKVE8ClvuVU+5LBey+DKb N3Hw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=YH4oGe9dRfdZQ1d4CvnTMZ1r7HRf2QBAQWpHy9E3Wng=; b=u3t5ZA7OmGEquAiTbZ6NO28cgdHuup2+60DwuaeuKXS3T280wJCozWfD9vCMBbyv1V av7MycYmcUh+8jcsadCusbw0iTPyQwO2GByQZSQUCHqSJyHvF6bBXl8CLhnMCllP6VFW 3q4eXn2R/JQCyTfwL+H681E5U200t+VjYzOOdDMIq44HVoevVzygMtB04WRcp0514MO3 1ojFZ/ZBP8a6IOoJ2giuGwEwkIyWfIUq1roHi4seQOks5SOMTuRRcnwRhEOjZF3YbC3M MmBGNVu/UzD6qriK6rgTy5g5EAgWBoQKc0VfbkOy4gJoFAO7rBCUWDsJ2Dwvg3JJXU8S cq3g== X-Gm-Message-State: AOAM5337zvXMzLAiyGbwiuFhy32aYADZCNcgA9JPNdqH9m42WgwroXBo KdogpAkBmHvnZQrUeYzhv6Vnkw== X-Google-Smtp-Source: ABdhPJzaVpRAohIh75kPuEB6cvjZHptUXsyrO2OyQP99Xt2V/uaZI2XjjHTplRgkBKRlsFA7V0q64g== X-Received: by 2002:a6b:8dd6:: with SMTP id p205mr14846469iod.192.1634579590519; Mon, 18 Oct 2021 10:53:10 -0700 (PDT) Received: from [192.168.1.30] ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id m15sm3303730ilh.73.2021.10.18.10.53.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 18 Oct 2021 10:53:10 -0700 (PDT) Subject: Re: don't use ->bd_inode to access the block device size v3 To: Christoph Hellwig Cc: Coly Li , Mike Snitzer , Song Liu , David Sterba , Josef Bacik , Theodore Ts'o , OGAWA Hirofumi , Dave Kleikamp , Ryusuke Konishi , Anton Altaparmakov , Konstantin Komarov , Kees Cook , Phillip Lougher , Jan Kara , linux-block@vger.kernel.org, dm-devel@redhat.com, drbd-dev@lists.linbit.com, linux-bcache@vger.kernel.org, linux-raid@vger.kernel.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, jfs-discussion@lists.sourceforge.net, linux-nfs@vger.kernel.org, linux-nilfs@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net, ntfs3@lists.linux.dev, reiserfs-devel@vger.kernel.org References: <20211018101130.1838532-1-hch@lst.de> <4a8c3a39-9cd3-5b2f-6d0f-a16e689755e6@kernel.dk> <20211018171843.GA3338@lst.de> <2f5dcf79-8419-45ff-c27c-68d43242ccfe@kernel.dk> <20211018174901.GA3990@lst.de> From: Jens Axboe Message-ID: Date: Mon, 18 Oct 2021 11:53:08 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20211018174901.GA3990@lst.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 10/18/21 11:49 AM, Christoph Hellwig wrote: > On Mon, Oct 18, 2021 at 11:40:51AM -0600, Jens Axboe wrote: >> static inline loff_t bdev_nr_bytes(struct block_device *bdev) >> { >> - return i_size_read(bdev->bd_inode); >> + return bdev->bd_nr_sectors; > > This hunk needs to go into bdev_nr_sectors, and the bdev_nr_bytes > probably wants to call bdev_nr_sectors and do the shifting. Makes sense. commit dd018a580d0037f65d7dd801cbf3e053f36283de Author: Jens Axboe Date: Mon Oct 18 11:39:45 2021 -0600 block: cache inode size in bdev Reading the inode size brings in a new cacheline for IO submit, and it's in the hot path being checked for every single IO. When doing millions of IOs per core per second, this is noticeable overhead. Cache the nr_sectors in the bdev itself. Signed-off-by: Jens Axboe diff --git a/block/genhd.c b/block/genhd.c index 759bc06810f8..53495e3391e3 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -58,6 +58,7 @@ void set_capacity(struct gendisk *disk, sector_t sectors) spin_lock(&bdev->bd_size_lock); i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT); + bdev->bd_nr_sectors = sectors; spin_unlock(&bdev->bd_size_lock); } EXPORT_SYMBOL(set_capacity); diff --git a/block/partitions/core.c b/block/partitions/core.c index 9dbddc355b40..66ef9bc6d6a1 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -91,6 +91,7 @@ static void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors) { spin_lock(&bdev->bd_size_lock); i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT); + bdev->bd_nr_sectors = sectors; spin_unlock(&bdev->bd_size_lock); } diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 472e55e0e94f..fe065c394fff 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -39,6 +39,7 @@ struct bio_crypt_ctx; struct block_device { sector_t bd_start_sect; + sector_t bd_nr_sectors; struct disk_stats __percpu *bd_stats; unsigned long bd_stamp; bool bd_read_only; /* read-only policy */ diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 7b0326661a1e..a967b3fb3c71 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -236,14 +236,14 @@ static inline sector_t get_start_sect(struct block_device *bdev) return bdev->bd_start_sect; } -static inline loff_t bdev_nr_bytes(struct block_device *bdev) +static inline sector_t bdev_nr_sectors(struct block_device *bdev) { - return i_size_read(bdev->bd_inode); + return bdev->bd_nr_sectors; } -static inline sector_t bdev_nr_sectors(struct block_device *bdev) +static inline loff_t bdev_nr_bytes(struct block_device *bdev) { - return bdev_nr_bytes(bdev) >> SECTOR_SHIFT; + return bdev_nr_setors(bdev) << SECTOR_SHIFT; } static inline sector_t get_capacity(struct gendisk *disk) -- Jens Axboe