From 7b9ca4c61bc278b771fb57d6290a31ab1fc7fdac Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 7 Aug 2017 13:19:50 +0200 Subject: 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 --- fs/ocfs2/quota_local.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'fs/ocfs2/quota_local.c') diff --git a/fs/ocfs2/quota_local.c b/fs/ocfs2/quota_local.c index 2eeedcc2e9da..aa700fd10610 100644 --- a/fs/ocfs2/quota_local.c +++ b/fs/ocfs2/quota_local.c @@ -521,7 +521,7 @@ static int ocfs2_recover_local_quota_file(struct inode *lqinode, goto out_drop_lock; } down_write(&sb_dqopt(sb)->dqio_sem); - spin_lock(&dq_data_lock); + spin_lock(&dquot->dq_dqb_lock); /* Add usage from quota entry into quota changes * of our node. Auxiliary variables are important * due to signedness */ @@ -529,7 +529,7 @@ static int ocfs2_recover_local_quota_file(struct inode *lqinode, inodechange = le64_to_cpu(dqblk->dqb_inodemod); dquot->dq_dqb.dqb_curspace += spacechange; dquot->dq_dqb.dqb_curinodes += inodechange; - spin_unlock(&dq_data_lock); + spin_unlock(&dquot->dq_dqb_lock); /* We want to drop reference held by the crashed * node. Since we have our own reference we know * global structure actually won't be freed. */ @@ -877,12 +877,12 @@ static void olq_set_dquot(struct buffer_head *bh, void *private) dqblk->dqb_id = cpu_to_le64(from_kqid(&init_user_ns, od->dq_dquot.dq_id)); - spin_lock(&dq_data_lock); + spin_lock(&od->dq_dquot.dq_dqb_lock); dqblk->dqb_spacemod = cpu_to_le64(od->dq_dquot.dq_dqb.dqb_curspace - od->dq_origspace); dqblk->dqb_inodemod = cpu_to_le64(od->dq_dquot.dq_dqb.dqb_curinodes - od->dq_originodes); - spin_unlock(&dq_data_lock); + spin_unlock(&od->dq_dquot.dq_dqb_lock); trace_olq_set_dquot( (unsigned long long)le64_to_cpu(dqblk->dqb_spacemod), (unsigned long long)le64_to_cpu(dqblk->dqb_inodemod), -- cgit v1.2.3