On Wed, 14 Aug 2013 16:22:18 -0400 Chris Metcalf <cmetcalf@xxxxxxxxxx> wrote: > This change makes lru_add_drain_all() only selectively interrupt > the cpus that have per-cpu free pages that can be drained. > > This is important in nohz mode where calling mlockall(), for > example, otherwise will interrupt every core unnecessarily. Changelog isn't very informative. I added this: : This is important on workloads where nohz cores are handling 10 Gb traffic : in userspace. Those CPUs do not enter the kernel and place pages into LRU : pagevecs and they really, really don't want to be interrupted, or they : drop packets on the floor. to attempt to describe the rationale for the patch. -- 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>