On Thu, 6 Feb 2014 11:41:36 -0500 Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > > Make the shadow lru->node[i].lock IRQ-safe to remove the order > dictated by interruption. This slightly increases the IRQ-disabled > section in the shadow shrinker, but it still drops all locks and > enables IRQ after every reclaimed shadow radix tree node. > > ... > > --- a/mm/workingset.c > +++ b/mm/workingset.c > @@ -273,7 +273,10 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker, > unsigned long max_nodes; > unsigned long pages; > > + local_irq_disable(); > shadow_nodes = list_lru_count_node(&workingset_shadow_nodes, sc->nid); > + local_irq_enable(); This is a bit ugly-looking. A reader will look at that and wonder why the heck we're disabling interrupts here. Against what? Is there some way in which we can clarify this? Perhaps adding list_lru_count_node_irq[save] and list_lru_walk_node_irq[save] would be better - is it reasonable to assume this is the only caller of the list_lru code which will ever want irq-safe treatment? This is all somewhat a side-effect of list_lru implementing its own locking rather than requiring caller-provided locking. It's always a mistake. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>