diff options
| author |   Jan Kara <jack@suse.cz> | 2017-08-07 13:19:50 +0200 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2017-08-17 22:07:59 +0200 |
| commit | 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac (patch) | |
| tree | 3e9c7464525efa2a9dd50d02e7fe8f7df45a4961 /include/linux/quota.h | |
| parent | fs: Provide __inode_get_bytes() (diff) | |
| download | wireguard-linux-7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac.tar.xz wireguard-linux-7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac.zip | |
quota: Reduce contention on dq_data_lock
dq_data_lock is currently used to protect all modifications of quota
accounting information, consistency of quota accounting on the inode,
and dquot pointers from inode. As a result contention on the lock can be
pretty heavy.
Reduce the contention on the lock by protecting quota accounting
information by a new dquot->dq_dqb_lock and consistency of quota
accounting with inode usage by inode->i_lock.
This change reduces time to create 500000 files on ext4 on ramdisk by 50
different processes in separate directories by 6% when user quota is
turned on. When those 50 processes belong to 50 different users, the
improvement is about 9%.
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'include/linux/quota.h')
| -rw-r--r-- | include/linux/quota.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/quota.h b/include/linux/quota.h index eccc1cb6274e..074123975595 100644 --- a/include/linux/quota.h +++ b/include/linux/quota.h @@ -298,12 +298,13 @@ struct dquot { struct list_head dq_free; /* Free list element */ struct list_head dq_dirty; /* List of dirty dquots */ struct mutex dq_lock; /* dquot IO lock */ + spinlock_t dq_dqb_lock; /* Lock protecting dq_dqb changes */ atomic_t dq_count; /* Use count */ struct super_block *dq_sb; /* superblock this applies to */ struct kqid dq_id; /* ID this applies to (uid, gid, projid) */ loff_t dq_off; /* Offset of dquot on disk */ unsigned long dq_flags; /* See DQ_* */ - struct mem_dqblk dq_dqb; /* Diskquota usage */ + struct mem_dqblk dq_dqb; /* Diskquota usage [dq_dqb_lock] */ }; /* Operations which must be implemented by each quota format */ |