Re: [PATCH 2/6] kill-the-BKL/reiserfs: release the write lockbefore rescheduling on do_journal_end()

From: Frederic Weisbecker
Date: Fri May 01 2009 - 18:20:28 EST


On Fri, May 01, 2009 at 03:31:48PM +0200, Frederic Weisbecker wrote:
> On Fri, May 01, 2009 at 09:09:11AM +0200, Ingo Molnar wrote:
> >
> > * Frederic Weisbecker <fweisbec@xxxxxxxxx> 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@xxxxxxxx>
> > > Cc: Chris Mason <chris.mason@xxxxxxxxxx>
> > > Cc: Alexander Beregalov <a.beregalov@xxxxxxxxx>
> > > Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> > > ---
> > > 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
>
> Indeed, that + the pattern suggested by Al.



s/Al/Andi

Sorry for the confusion.


> Thanks.
>

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