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 5F76AC4167B for ; Mon, 18 Oct 2021 17:53:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4CD1161077 for ; Mon, 18 Oct 2021 17:53:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232873AbhJRRzY (ORCPT ); Mon, 18 Oct 2021 13:55:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39854 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231961AbhJRRzW (ORCPT ); Mon, 18 Oct 2021 13:55:22 -0400 Received: from mail-io1-xd30.google.com (mail-io1-xd30.google.com [IPv6:2607:f8b0:4864:20::d30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E6C8C061769 for ; Mon, 18 Oct 2021 10:53:11 -0700 (PDT) Received: by mail-io1-xd30.google.com with SMTP id r134so17263230iod.11 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=brCuX1oGr86+Il40SRkbSfGWjBh4vwZY1lG61Xn79dOLYwxYM6ykQhmUdfFyolldjE 7YffxpPGuFC29opSTZcyvipzAO7QIUapOMQ6fYOiLComkL6Pd2MSgsSL4oj2uJY3/ezu GQShl11uiGe9BVSMNZlmAvKJpEr7xPxb4jjm4akrJ2/Dd4uOFJBMCAVkGLjy2kai0TBp zQzboBVkbazWnZXdhmsnT4PTVZ0qstoTRTjUhZZvdQF5V3HU08SQA7CkDd1MMDl9eXU3 39qiyNKe41XkZ+pjcFy5K6tg3ugt/xqoqcK16O2YcdR7FduUcmK02SRwW4jimzUuxKnF 5Wvg== X-Gm-Message-State: AOAM5339c+VKG1DwpVlC+NZW0wGltdqdO2F3HZeEHQur6I+OZXCK6Ju1 NvHPXuGT7bmDPKkhLytjmCt6TA== 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-scsi@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