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author | Wang Shilong <wangsl-fnst@cn.fujitsu.com> | 2013-05-06 11:03:27 (GMT) |
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committer | Josef Bacik <jbacik@fusionio.com> | 2013-06-14 15:29:21 (GMT) |
commit | 1e8f915868c59be4d6e49d9aff928454a5d5d569 (patch) | |
tree | e797287ad09f0537f5c5e1901f6353dcbdd4ff2f /fs/btrfs/ctree.h | |
parent | 85965600f50b2e57746363d0ace4ab6b2bcb9c27 (diff) | |
download | linux-fsl-qoriq-1e8f915868c59be4d6e49d9aff928454a5d5d569.tar.xz |
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/ctree.h')
-rw-r--r-- | fs/btrfs/ctree.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index d6dd49b..a365400 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1594,6 +1594,12 @@ struct btrfs_fs_info { struct rb_root qgroup_tree; spinlock_t qgroup_lock; + /* + * used to avoid frequently calling ulist_alloc()/ulist_free() + * when doing qgroup accounting, it must be protected by qgroup_lock. + */ + struct ulist *qgroup_ulist; + /* protect user change for quota operations */ struct mutex qgroup_ioctl_lock; |