From: Jan Kara <jack@suse.cz>
To: Theodore Ts'o <tytso@mit.edu>
Cc: Ext4 Developers List <linux-ext4@vger.kernel.org>
Subject: Re: [PATCH 1/2] jbd2: don't call get_bh() before calling __jbd2_journal_remove_checkpoint()
Date: Wed, 3 Sep 2014 18:08:37 +0200 [thread overview]
Message-ID: <20140903160837.GC17066@quack.suse.cz> (raw)
In-Reply-To: <1409698000-18126-1-git-send-email-tytso@mit.edu>
On Tue 02-09-14 18:46:39, Ted Tso wrote:
> The __jbd2_journal_remove_checkpoint() doesn't require an elevated
> b_count; indeed, until the jh structure gets released by the call to
> jbd2_journal_put_journal_head(), the bh's b_count is elevated by
> virtue of the existence of the jh structure.
>
> Suggested-by: Jan Kara <jack@suse.cz>
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Looks good so you can add:
Reviewed-by: Jan Kara <jack@suse.cz>
Just we can do a bit more as I mentioned in my other email:
> @@ -359,8 +354,9 @@ restart2:
> * know that it has been written out and so we can
> * drop it from the list
> */
> - done = __jbd2_journal_remove_checkpoint(jh);
> __brelse(bh);
Here we don't need to grab bh reference unless we are going to call
wait_on_buffer(). Which moves get_bh / __brelse out of fast path.
> + if (__jbd2_journal_remove_checkpoint(jh))
> + break;
> }
> out:
> spin_unlock(&journal->j_list_lock);
Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
next prev parent reply other threads:[~2014-09-03 16:08 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-02 17:18 [PATCH] jbd2: Optimize jbd2_log_do_checkpoint() a bit Jan Kara
2014-09-02 21:59 ` Theodore Ts'o
2014-09-02 22:46 ` [PATCH 1/2] jbd2: don't call get_bh() before calling __jbd2_journal_remove_checkpoint() Theodore Ts'o
2014-09-02 22:46 ` [PATCH 2/2] jbd2: optimize jbd2_log_do_checkpoint() a bit Theodore Ts'o
2014-09-03 7:54 ` [PATCH 1/2] jbd2: don't call get_bh() before calling __jbd2_journal_remove_checkpoint() Yuanhan Liu
2014-09-03 16:08 ` Jan Kara [this message]
2014-09-03 18:38 ` [PATCH -v2] " Theodore Ts'o
[not found] ` <CAGZGoEfjAZuOAbp-AqA-kiL2aTwiRXDO_Di=LPDovRBDNSn5dw@mail.gmail.com>
2014-09-03 17:30 ` [PATCH 1/2] " Theodore Ts'o
2014-09-03 16:03 ` [PATCH] jbd2: Optimize jbd2_log_do_checkpoint() a bit Jan Kara
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