Re: [PATCH] dax: Fix missed PMD wakeups

From: Jan Kara
Date: Fri Jul 12 2019 - 05:13:59 EST


On Thu 11-07-19 08:25:50, Matthew Wilcox wrote:
> On Thu, Jul 11, 2019 at 07:13:50AM -0700, Matthew Wilcox wrote:
> > However, the XA_RETRY_ENTRY might be a good choice. It doesn't normally
> > appear in an XArray (it may appear if you're looking at a deleted node,
> > but since we're holding the lock, we can't see deleted nodes).
>
...

> @@ -254,7 +267,7 @@ static void wait_entry_unlocked(struct xa_state *xas, void *entry)
> static void put_unlocked_entry(struct xa_state *xas, void *entry)
> {
> /* If we were the only waiter woken, wake the next one */
> - if (entry)
> + if (entry && dax_is_conflict(entry))

This should be !dax_is_conflict(entry)...

> dax_wake_entry(xas, entry, false);
> }

Otherwise the patch looks good to me so feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

once you fix this.

Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR