From 9077abd06e4b1acba5d88668c4407a6f4e265d83 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 9 Jul 2013 22:36:45 +0800 Subject: writeback: Do not sort b_io list only because of block device inode 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 +++++--- 2 files changed, 6 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/block_dev.c b/fs/block_dev.c index 442e29fd8..4d2257275 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -666,7 +666,7 @@ 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 b4d9b7f1e..90aabfa44 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -69,7 +69,7 @@ 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; @@ -264,11 +264,13 @@ 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 */ -- cgit v1.2.3