From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753165Ab3FXIH4 (ORCPT ); Mon, 24 Jun 2013 04:07:56 -0400 Received: from cantor2.suse.de ([195.135.220.15]:38325 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752893Ab3FXIHx (ORCPT ); Mon, 24 Jun 2013 04:07:53 -0400 From: Jan Kara To: Wu Fengguang Cc: linux-fsdevel@vger.kernel.org, LKML , Jan Kara Subject: [PATCH] writeback: Do not sort b_io list only because of block device inode Date: Mon, 24 Jun 2013 10:07:49 +0200 Message-Id: <1372061269-16663-1-git-send-email-jack@suse.cz> X-Mailer: git-send-email 1.8.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is very likely that block device inode will be part of BDI dirty list as well. However it doesn't make sence to sort inodes on the b_io list just because of this inode (as it contains buffers all over the device anyway). So save some CPU cycles which is valuable since we hold relatively contented wb->list_lock. Signed-off-by: Jan Kara --- fs/block_dev.c | 2 +- fs/fs-writeback.c | 8 +++++--- include/linux/fs.h | 6 ++++++ 3 files changed, 12 insertions(+), 4 deletions(-) diff --git a/fs/block_dev.c b/fs/block_dev.c index 2091db8..2562330 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -606,7 +606,7 @@ static struct block_device *bd_acquire(struct inode *inode) return bdev; } -static inline int sb_is_blkdev_sb(struct super_block *sb) +int sb_is_blkdev_sb(struct super_block *sb) { return sb == blockdev_superblock; } diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 3be5718..cabdece 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -68,7 +68,7 @@ static inline struct backing_dev_info *inode_to_bdi(struct inode *inode) { struct super_block *sb = inode->i_sb; - if (strcmp(sb->s_type->name, "bdev") == 0) + if (sb_is_blkdev_sb(sb)) return inode->i_mapping->backing_dev_info; return sb->s_bdi; @@ -250,11 +250,13 @@ static int move_expired_inodes(struct list_head *delaying_queue, if (work->older_than_this && inode_dirtied_after(inode, *work->older_than_this)) break; + list_move(&inode->i_wb_list, &tmp); + moved++; + if (sb_is_blkdev_sb(inode->i_sb)) + continue; if (sb && sb != inode->i_sb) do_sb_sort = 1; sb = inode->i_sb; - list_move(&inode->i_wb_list, &tmp); - moved++; } /* just one sb in list, splice to dispatch_queue and we're done */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 43db02e..8f897d0 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2058,6 +2058,7 @@ extern struct super_block *freeze_bdev(struct block_device *); extern void emergency_thaw_all(void); extern int thaw_bdev(struct block_device *bdev, struct super_block *sb); extern int fsync_bdev(struct block_device *); +extern int sb_is_blkdev_sb(struct super_block *sb); #else static inline void bd_forget(struct inode *inode) {} static inline int sync_blockdev(struct block_device *bdev) { return 0; } @@ -2077,6 +2078,11 @@ static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb) static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg) { } + +static inline int sb_is_blkdev_sb(struct super_block *sb) +{ + return 0; +} #endif extern int sync_filesystem(struct super_block *); extern const struct file_operations def_blk_fops; -- 1.8.1.4