On Thu, Jun 07 2018 at 11:48am -0400, Mikulas Patocka <[email protected]> wrote:
> This is second version of this patch - it also removes the label > continue_locked, because it is no longer needed. If forgot to refresh the > patch before sending it, so I sent an olded version. > > > From: Mikulas Patocka <[email protected]> > Subject: [patch 2/3 v2] dm-writecache: convert wait queue to wake_up_process > > If there's just one process that can wait on a queue, we can use > wake_up_process. According to Linus, it is safe to call wake_up_process > on a process even if the process may be doing something else. > > Signed-off-by: Mikulas Patocka <[email protected]> > > --- > drivers/md/dm-writecache.c | 34 +++++++++++++++------------------- > 1 file changed, 15 insertions(+), 19 deletions(-) > > Index: linux-2.6/drivers/md/dm-writecache.c > =================================================================== > --- linux-2.6.orig/drivers/md/dm-writecache.c 2018-06-05 22:54:49.000000000 > +0200 > +++ linux-2.6/drivers/md/dm-writecache.c 2018-06-07 17:44:11.000000000 > +0200 > @@ -1273,10 +1272,11 @@ static void writecache_writeback_endio(s > struct dm_writecache *wc = wb->wc; > unsigned long flags; > > - raw_spin_lock_irqsave(&wc->endio_thread_wait.lock, flags); > + raw_spin_lock_irqsave(&wc->endio_list_lock, flags); > + if (unlikely(list_empty(&wc->endio_list))) > + wake_up_process(wc->endio_thread); > list_add_tail(&wb->endio_entry, &wc->endio_list); > - swake_up_locked(&wc->endio_thread_wait); > - raw_spin_unlock_irqrestore(&wc->endio_thread_wait.lock, flags); > + raw_spin_unlock_irqrestore(&wc->endio_list_lock, flags); > } I'm not following the logic you're using for the above pattern of using wake_up_process if the list is empty.. seems unintuitive. Given you add to the list (be it endio here, or flush elsewhere), why not just add to the list and then always wake_up_process()? Mike -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
