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author | Chris Mason <chris.mason@oracle.com> | 2008-09-29 15:18:18 -0400 |
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committer | Chris Mason <chris.mason@oracle.com> | 2008-09-29 15:18:18 -0400 |
commit | d352ac68148b69937d39ca5d48bcc4478e118dbf (patch) | |
tree | 7951dd7311999d9e77766acdc7f8e93de97874d8 /fs/btrfs/async-thread.c | |
parent | 9a5e1ea1e1e539e244a54afffc330fc368376ab9 (diff) | |
download | linux-d352ac68148b69937d39ca5d48bcc4478e118dbf.tar.bz2 |
Btrfs: add and improve comments
This improves the comments at the top of many functions. It didn't
dive into the guts of functions because I was trying to
avoid merging problems with the new allocator and back reference work.
extent-tree.c and volumes.c were both skipped, and there is definitely
more work todo in cleaning and commenting the code.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/async-thread.c')
-rw-r--r-- | fs/btrfs/async-thread.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/fs/btrfs/async-thread.c b/fs/btrfs/async-thread.c index 4e780b279de6..04fb9702d14c 100644 --- a/fs/btrfs/async-thread.c +++ b/fs/btrfs/async-thread.c @@ -231,17 +231,25 @@ static struct btrfs_worker_thread *next_worker(struct btrfs_workers *workers) /* * if we pick a busy task, move the task to the end of the list. - * hopefully this will keep things somewhat evenly balanced + * hopefully this will keep things somewhat evenly balanced. + * Do the move in batches based on the sequence number. This groups + * requests submitted at roughly the same time onto the same worker. */ next = workers->worker_list.next; worker = list_entry(next, struct btrfs_worker_thread, worker_list); atomic_inc(&worker->num_pending); worker->sequence++; + if (worker->sequence % workers->idle_thresh == 0) list_move_tail(next, &workers->worker_list); return worker; } +/* + * selects a worker thread to take the next job. This will either find + * an idle worker, start a new worker up to the max count, or just return + * one of the existing busy workers. + */ static struct btrfs_worker_thread *find_worker(struct btrfs_workers *workers) { struct btrfs_worker_thread *worker; |