Messages in this thread | | | Date | Wed, 14 Aug 2013 14:12:58 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH v8] mm: make lru_add_drain_all() selective |
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On Wed, 14 Aug 2013 16:22:18 -0400 Chris Metcalf <cmetcalf@tilera.com> 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.
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