xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

writeback: trace event writeback_queue_io

Browse Source 
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>
This commit is contained in:
Wu Fengguang
2011-04-23 12:27:27 -06:00
parent 251d6a471c
commit e84d0a4f8e
2 changed files with 35 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
fs/fs-writeback.c
View File

@@ -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)