]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commitdiff
writeback: improve scalability of bdi writeback work queues
authorNick Piggin <npiggin@suse.de>
Tue, 15 Sep 2009 19:34:12 +0000 (21:34 +0200)
committerJens Axboe <jens.axboe@oracle.com>
Wed, 16 Sep 2009 13:18:52 +0000 (15:18 +0200)
If you're going to do an atomic RMW on each list entry, there's not much
point in all the RCU complexities of the list walking. This is only going
to help the multi-thread case I guess, but it doesn't hurt to do now.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
fs/fs-writeback.c

index 59c99e7291874cb33315aa4873e8dd0c35c91483..6bca6f8176f0d8f105be5379b31837bf85f27da1 100644 (file)
@@ -772,8 +772,9 @@ static struct bdi_work *get_next_work_item(struct backing_dev_info *bdi,
        rcu_read_lock();
 
        list_for_each_entry_rcu(work, &bdi->work_list, list) {
-               if (!test_and_clear_bit(wb->nr, &work->seen))
+               if (!test_bit(wb->nr, &work->seen))
                        continue;
+               clear_bit(wb->nr, &work->seen);
 
                ret = work;
                break;