From patchwork Fri Apr 15 04:52:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 562998 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC915C43219 for ; Fri, 15 Apr 2022 04:58:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350291AbiDOFAf (ORCPT ); Fri, 15 Apr 2022 01:00:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349860AbiDOE6q (ORCPT ); Fri, 15 Apr 2022 00:58:46 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB2EDF0B; Thu, 14 Apr 2022 21:54:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=eypoqjBCbHteIGJMjEE77faduCfiNIsAQ0ydQeu7OQ0=; b=yel/I7wJHKQGgU++DGlNr4s6By PhYVQZj76IsIJmZMeImq5Q6B2/aQRkMD3ug5dWOU3Jeh5aspjbtIuEjPut08JeM1WmCeQvYQ+tJ0f U696Xi8dd1qtuDaSpjLkD+EO876944juvaQn7mqYu4AmZhVRFKFIBWZURNzhkvK80mkS4SdYE8ghg 5kwkeIFA+dIpz0sffz1xoP4BK6LoTUtTMKLOpm6yB1H7oV7nfL4grqbNBsJP5+jCEy6k9Hq/bQASA 9dlkqzozrnkdCC5ckIaWKU5KZigzG6TnQjnKvn/KI4zIY9eR4oRyKCNwIxfdzpwno3WYuY2QxxbuI z9ygJJXA==; Received: from [2a02:1205:504b:4280:f5dd:42a4:896c:d877] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1nfDyR-008Ptb-2k; Fri, 15 Apr 2022 04:54:23 +0000 From: Christoph Hellwig To: Jens Axboe Cc: dm-devel@redhat.com, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-um@lists.infradead.org, linux-block@vger.kernel.org, drbd-dev@lists.linbit.com, nbd@other.debian.org, ceph-devel@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, linux-bcache@vger.kernel.org, linux-raid@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mtd@lists.infradead.org, linux-nvme@lists.infradead.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, jfs-discussion@lists.sourceforge.net, linux-nilfs@vger.kernel.org, ntfs3@lists.linux.dev, ocfs2-devel@oss.oracle.com, linux-mm@kvack.org Subject: [PATCH 27/27] direct-io: remove random prefetches Date: Fri, 15 Apr 2022 06:52:58 +0200 Message-Id: <20220415045258.199825-28-hch@lst.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220415045258.199825-1-hch@lst.de> References: <20220415045258.199825-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Randomly poking into block device internals for manual prefetches isn't exactly a very maintainable thing to do. And none of the performance criticil direct I/O implementations still use this library function anyway, so just drop it. Signed-off-by: Christoph Hellwig Reviewed-by: David Sterba --- fs/direct-io.c | 32 ++++---------------------------- 1 file changed, 4 insertions(+), 28 deletions(-) diff --git a/fs/direct-io.c b/fs/direct-io.c index aef06e607b405..840752006f601 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1115,11 +1115,10 @@ static inline int drop_refcount(struct dio *dio) * individual fields and will generate much worse code. This is important * for the whole file. */ -static inline ssize_t -do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, - struct block_device *bdev, struct iov_iter *iter, - get_block_t get_block, dio_iodone_t end_io, - dio_submit_t submit_io, int flags) +ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, + struct block_device *bdev, struct iov_iter *iter, + get_block_t get_block, dio_iodone_t end_io, + dio_submit_t submit_io, int flags) { unsigned i_blkbits = READ_ONCE(inode->i_blkbits); unsigned blkbits = i_blkbits; @@ -1334,29 +1333,6 @@ do_blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, kmem_cache_free(dio_cache, dio); return retval; } - -ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, - struct block_device *bdev, struct iov_iter *iter, - get_block_t get_block, - dio_iodone_t end_io, dio_submit_t submit_io, - int flags) -{ - /* - * The block device state is needed in the end to finally - * submit everything. Since it's likely to be cache cold - * prefetch it here as first thing to hide some of the - * latency. - * - * Attempt to prefetch the pieces we likely need later. - */ - prefetch(&bdev->bd_disk->part_tbl); - prefetch(bdev->bd_disk->queue); - prefetch((char *)bdev->bd_disk->queue + SMP_CACHE_BYTES); - - return do_blockdev_direct_IO(iocb, inode, bdev, iter, get_block, - end_io, submit_io, flags); -} - EXPORT_SYMBOL(__blockdev_direct_IO); static __init int dio_init(void)