On Wed, 25 Jun 2014 08:58:48 +0100 Mel Gorman <mgorman@xxxxxxx> wrote: > @@ -325,7 +321,14 @@ static unsigned long zone_dirty_limit(struct zone *zone) > */ > bool zone_dirty_ok(struct zone *zone) > { > - unsigned long limit = zone_dirty_limit(zone); > + unsigned long limit = zone->dirty_limit_cached; > + struct task_struct *tsk = current; > + > + if (tsk->flags & PF_LESS_THROTTLE || rt_task(tsk)) { > + limit = zone_dirty_limit(zone); > + zone->dirty_limit_cached = limit; > + limit += limit / 4; > + } Could we get a comment in here explaining what we're doing and why PF_LESS_THROTTLE and rt_task control whether we do it? -- 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>