From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH 2/6] kill-the-BKL/reiserfs: release the write lock
	before rescheduling on do_journal_end()
Date: Fri, 1 May 2009 09:09:11 +0200
Message-ID: <20090501070911.GG5983@elte.hu>
References: <1241145862-21700-1-git-send-email-fweisbec@gmail.com> <1241145862-21700-3-git-send-email-fweisbec@gmail.com>
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To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>, Jeff Mahoney <jeffm@suse.com>, ReiserFS Development List <reiserfs-devel@vger.kernel.org>, Chris Mason <chris.mason@oracle.com>, Alexander Beregalov <a.beregalov@gmail.com>, Alessio Igor Bogani <abogani@texware.it>, Jonathan Corbet <corbet@lwn.net>, Alexander Viro <viro@zeniv.linux.org.uk>


* Frederic Weisbecker <fweisbec@gmail.com> wrote:

> When do_journal_end() copies data to the journal blocks buffers in memory,
> it reschedules if needed between each block copied and dirtyfied.
> 
> We can also release the write lock at this rescheduling stage,
> like did the bkl implicitly.
> 
> [ Impact: release the reiserfs write lock when it is not needed ]
> 
> Cc: Jeff Mahoney <jeffm@suse.com>
> Cc: Chris Mason <chris.mason@oracle.com>
> Cc: Alexander Beregalov <a.beregalov@gmail.com>
> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> ---
>  fs/reiserfs/journal.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
> index 7976d7d..373d080 100644
> --- a/fs/reiserfs/journal.c
> +++ b/fs/reiserfs/journal.c
> @@ -4232,7 +4232,9 @@ static int do_journal_end(struct reiserfs_transaction_handle *th,
>  		next = cn->next;
>  		free_cnode(sb, cn);
>  		cn = next;
> +		reiserfs_write_unlock(sb);
>  		cond_resched();
> +		reiserfs_write_lock(sb);

There's 8 cond_resched()'s in the code - i'd suggest to introduce a 
helper for this - reiserfs_write_cond_resched(sb) or so?

	Ingo