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| author |   Wang Shilong <wangsl-fnst@cn.fujitsu.com> | 2013-05-06 11:03:27 +0000 |
|---|---|---|
| committer |   Josef Bacik <jbacik@fusionio.com> | 2013-06-14 11:29:21 -0400 |
| commit | 1e8f915868c59be4d6e49d9aff928454a5d5d569 (patch) | |
| tree | e797287ad09f0537f5c5e1901f6353dcbdd4ff2f /fs/btrfs/disk-io.c | |
| parent | btrfs: show compiled-in config features at module load time (diff) | |
| download | linux-dev-1e8f915868c59be4d6e49d9aff928454a5d5d569.tar.xz linux-dev-1e8f915868c59be4d6e49d9aff928454a5d5d569.zip | |
Btrfs: introduce qgroup_ulist to avoid frequently allocating/freeing ulist
When doing qgroup accounting, we call ulist_alloc()/ulist_free() every time
when we want to walk qgroup tree.
By introducing 'qgroup_ulist', we only need to call ulist_alloc()/ulist_free()
once. This reduce some sys time to allocate memory, see the measurements below
fsstress -p 4 -n 10000 -d $dir
With this patch:
real 0m50.153s
user 0m0.081s
sys 0m6.294s
real 0m51.113s
user 0m0.092s
sys 0m6.220s
real 0m52.610s
user 0m0.096s
sys 0m6.125s avg 6.213
-----------------------------------------------------
Without the patch:
real 0m54.825s
user 0m0.061s
sys 0m10.665s
real 1m6.401s
user 0m0.089s
sys 0m11.218s
real 1m13.768s
user 0m0.087s
sys 0m10.665s avg 10.849
we can see the sys time reduce ~43%.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Diffstat (limited to 'fs/btrfs/disk-io.c')
| -rw-r--r-- | fs/btrfs/disk-io.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index aecf788ed81e..df5169b7aad1 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2274,6 +2274,7 @@ int open_ctree(struct super_block *sb, fs_info->qgroup_seq = 1; fs_info->quota_enabled = 0; fs_info->pending_quota_state = 0; + fs_info->qgroup_ulist = NULL; mutex_init(&fs_info->qgroup_rescan_lock); btrfs_init_free_cluster(&fs_info->meta_alloc_cluster); |