jbd2: Change j_state_lock to be a rwlock_t
Lockstat reports have shown that j_state_lock is a major source of
lock contention, especially on systems with more than 4 CPU cores. So
change it to be a read/write spinlock.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index 47878cf..9c1b92e 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -760,13 +760,13 @@
if (osb->osb_commit_interval)
commit_interval = osb->osb_commit_interval;
- spin_lock(&journal->j_state_lock);
+ write_lock(&journal->j_state_lock);
journal->j_commit_interval = commit_interval;
if (osb->s_mount_opt & OCFS2_MOUNT_BARRIER)
journal->j_flags |= JBD2_BARRIER;
else
journal->j_flags &= ~JBD2_BARRIER;
- spin_unlock(&journal->j_state_lock);
+ write_unlock(&journal->j_state_lock);
}
int ocfs2_journal_init(struct ocfs2_journal *journal, int *dirty)