From: Ted Ts'o <tytso@mit.edu>
To: Jan Kara <jack@suse.cz>
Cc: Ext4 Developers List <linux-ext4@vger.kernel.org>,
ocfs2-devel@oss.oracle.com, John Stultz <johnstul@us.ibm.com>,
Keith Maanthey <kmannth@us.ibm.com>,
Eric Whitney <eric.whitney@hp.com>
Subject: Re: [PATCH -v2 1/3] jbd2: Use atomic variables to avoid taking t_handle_lock in jbd2_journal_stop
Date: Tue, 10 Aug 2010 12:30:46 -0400 [thread overview]
Message-ID: <20100810163046.GM3635@thunk.org> (raw)
In-Reply-To: <20100809194554.GB5356@quack.suse.cz>
On Mon, Aug 09, 2010 at 09:45:55PM +0200, Jan Kara wrote:
> Ah, OK. You're right. I just thought we eventually want to remove the
> lock but you're right that currently the code is fine. Sorry for the noise.
I would love to get rid of the j_state_lock, but looking through the
code, I couldn't figure out how to do this safely. Hence my
conversion of the j_state_lock to a rwlock_t, with the downside of
this causing more cache line bounces. If someone can suggest a way to
drop needing a global spinlock (whether it is an exclusive or rwlock)
in start_this_handle(), I'd love to hear them.
- Ted
next prev parent reply other threads:[~2010-08-10 16:30 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-04 16:39 [PATCH -v2 0/3] jbd2 scalability patches Theodore Ts'o
2010-08-04 16:39 ` [PATCH -v2 1/3] jbd2: Use atomic variables to avoid taking t_handle_lock in jbd2_journal_stop Theodore Ts'o
2010-08-09 17:02 ` Jan Kara
2010-08-09 19:05 ` Ted Ts'o
2010-08-09 19:45 ` Jan Kara
2010-08-10 16:30 ` Ted Ts'o [this message]
2010-08-11 22:16 ` Jan Kara
2010-08-04 16:39 ` [PATCH -v2 2/3] jbd2: Change j_state_lock to be a rwlock_t Theodore Ts'o
2010-08-04 16:39 ` [PATCH -v2 3/3] jbd2: Remove t_handle_lock from start_this_handle() Theodore Ts'o
2010-08-05 1:58 ` [PATCH -v2 0/3] jbd2 scalability patches john stultz
2010-08-05 5:42 ` Ted Ts'o
2010-08-05 17:42 ` john stultz
2010-08-09 16:06 ` [Ocfs2-devel] " Joel Becker
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