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| author | Chris Mason <chris.mason@oracle.com> | 2011-07-16 15:23:14 -0400 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2011-07-27 12:46:46 -0400 |
| commit | bd681513fa6f2ff29aa391f01e413a2d1c59fd77 (patch) | |
| tree | bb10ec6ef876b4d7a553cbe54976ec49a0d10b21 /fs/btrfs/delayed-inode.c | |
| parent | 81317fdeddcef259b6ecf7b5c0d04caa167c6b54 (diff) | |
| download | linux-bd681513fa6f2ff29aa391f01e413a2d1c59fd77.tar.bz2 | |
Btrfs: switch the btrfs tree locks to reader/writer
The btrfs metadata btree is the source of significant
lock contention, especially in the root node. This
commit changes our locking to use a reader/writer
lock.
The lock is built on top of rw spinlocks, and it
extends the lock tracking to remember if we have a
read lock or a write lock when we go to blocking. Atomics
count the number of blocking readers or writers at any
given time.
It removes all of the adaptive spinning from the old code
and uses only the spinning/blocking hints inside of btrfs
to decide when it should continue spinning.
In read heavy workloads this is dramatically faster. In write
heavy workloads we're still faster because of less contention
on the root node lock.
We suffer slightly in dbench because we schedule more often
during write locks, but all other benchmarks so far are improved.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/delayed-inode.c')
| -rw-r--r-- | fs/btrfs/delayed-inode.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c index 98c68e658a9b..b52c672f4c18 100644 --- a/fs/btrfs/delayed-inode.c +++ b/fs/btrfs/delayed-inode.c @@ -735,7 +735,7 @@ static int btrfs_batch_insert_items(struct btrfs_trans_handle *trans, } /* reset all the locked nodes in the patch to spinning locks. */ - btrfs_clear_path_blocking(path, NULL); + btrfs_clear_path_blocking(path, NULL, 0); /* insert the keys of the items */ ret = setup_items_for_insert(trans, root, path, keys, data_size, |