[Ocfs2-devel] [PATCH, RFC 2/3] jbd2: Change j_state_lock to be a rwlock_t

[Ted Ts'o]

On Tue, Aug 03, 2010 at 12:01:54PM -0400, Theodore Ts'o wrote:
> 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 at mit.edu>

Oops, this patch can result in a BUG_ON in fs/jbd2/transaction.c.  I'm
currently testing a fix/replacement patch, but I figured I send a
quick warning to folks not to waste time trying this out just yet.  I
should hopefully have a new, better-tested patch in by tomorrow
morning.

						- Ted