Gitweb:     http://git.kernel.org/linus/77fad5e625e56eb31a343ae1d489979fdc61a2aa
Commit:     77fad5e625e56eb31a343ae1d489979fdc61a2aa
Parent:     deed62edffe600bc5b379c872d3004116e001b66
Author:     Nick Piggin <npiggin@suse.de>
AuthorDate: Tue Sep 15 21:34:12 2009 +0200
Committer:  Jens Axboe <jens.axboe@oracle.com>
CommitDate: Wed Sep 16 15:18:52 2009 +0200

    writeback: improve scalability of bdi writeback work queues
    
    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 |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 59c99e7..6bca6f8 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -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;
--
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html