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| author | Wu Fengguang <fengguang.wu@intel.com> | 2011-04-23 22:27:27 +0400 |
|---|---|---|
| committer | Wu Fengguang <fengguang.wu@intel.com> | 2011-06-08 04:25:23 +0400 |
| commit | e84d0a4f8e39a73003a6ec9a11b07702745f4c1f (patch) | |
| tree | 2319765d78502d13101ac50bafb0ba5577133092 /fs/fs-writeback.c | |
| parent | 251d6a471c831e22880b3c146bb4556ddfb1dc82 (diff) | |
| download | linux-e84d0a4f8e39a73003a6ec9a11b07702745f4c1f.tar.xz | |
writeback: trace event writeback_queue_io
Note that it adds a little overheads to account the moved/enqueued
inodes from b_dirty to b_io. The "moved" accounting may be later used to
limit the number of inodes that can be moved in one shot, in order to
keep spinlock hold time under control.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Diffstat (limited to 'fs/fs-writeback.c')
| -rw-r--r-- | fs/fs-writeback.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 5185fad48b62..6caa98247a5b 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -248,15 +248,16 @@ static bool inode_dirtied_after(struct inode *inode, unsigned long t) /* * Move expired dirty inodes from @delaying_queue to @dispatch_queue. */ -static void move_expired_inodes(struct list_head *delaying_queue, +static int move_expired_inodes(struct list_head *delaying_queue, struct list_head *dispatch_queue, - unsigned long *older_than_this) + unsigned long *older_than_this) { LIST_HEAD(tmp); struct list_head *pos, *node; struct super_block *sb = NULL; struct inode *inode; int do_sb_sort = 0; + int moved = 0; while (!list_empty(delaying_queue)) { inode = wb_inode(delaying_queue->prev); @@ -267,12 +268,13 @@ static void move_expired_inodes(struct list_head *delaying_queue, 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 */ if (!do_sb_sort) { list_splice(&tmp, dispatch_queue); - return; + goto out; } /* Move inodes from one superblock together */ @@ -284,6 +286,8 @@ static void move_expired_inodes(struct list_head *delaying_queue, list_move(&inode->i_wb_list, dispatch_queue); } } +out: + return moved; } /* @@ -299,9 +303,11 @@ static void move_expired_inodes(struct list_head *delaying_queue, */ static void queue_io(struct bdi_writeback *wb, unsigned long *older_than_this) { + int moved; assert_spin_locked(&wb->list_lock); list_splice_init(&wb->b_more_io, &wb->b_io); - move_expired_inodes(&wb->b_dirty, &wb->b_io, older_than_this); + moved = move_expired_inodes(&wb->b_dirty, &wb->b_io, older_than_this); + trace_writeback_queue_io(wb, older_than_this, moved); } static int write_inode(struct inode *inode, struct writeback_control *wbc) |