On Mon, Aug 12, 2019 at 08:52:23PM -0400, Daniel Jordan wrote:
>
> @@ -191,22 +184,25 @@ static struct padata_priv *padata_get_next(struct parallel_data *pd)
> padata = list_entry(reorder->list.next,
> struct padata_priv, list);
>
> - list_del_init(&padata->list);
> - atomic_dec(&pd->reorder_objects);
> + /*
> + * The check fails in the unlikely event that two or more
> + * parallel jobs have hashed to the same CPU and one of the
> + * later ones finishes first.
> + */
> + if (padata->seq_nr == pd->processed) {
> + list_del_init(&padata->list);
> + atomic_dec(&pd->reorder_objects);
Now that you've changed the test for whether there is work to be
done you also need to update the code at the end of padata_reorder
that checks whether there is work to do. Otherwise we can end up
in a busy loop that just wastes CPU cycles.
Cheers,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
