Messages in this thread | | | Date | Wed, 9 Feb 2022 10:38:28 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v6 0/2] Adjust NUMA imbalance for multiple LLCs |
| |
On Tue, Feb 08, 2022 at 09:43:32AM +0000, Mel Gorman wrote: > Changelog sinve v5 > o Fix off-by-one error > > Changelog since V4 > o Scale imbalance based on the top domain that prefers siblings > o Keep allowed imbalance as 2 up to the point where LLCs can be overloaded > > Changelog since V3 > o Calculate imb_numa_nr for multiple SD_NUMA domains > o Restore behaviour where communicating pairs remain on the same node > > Commit 7d2b5dd0bcc4 ("sched/numa: Allow a floating imbalance between NUMA > nodes") allowed an imbalance between NUMA nodes such that communicating > tasks would not be pulled apart by the load balancer. This works fine when > there is a 1:1 relationship between LLC and node but can be suboptimal > for multiple LLCs if independent tasks prematurely use CPUs sharing cache. > > The series addresses two problems -- inconsistent logic when allowing a > NUMA imbalance and sub-optimal performance when there are many LLCs per > NUMA node. > > include/linux/sched/topology.h | 1 + > kernel/sched/fair.c | 30 ++++++++++--------- > kernel/sched/topology.c | 53 ++++++++++++++++++++++++++++++++++ > 3 files changed, 71 insertions(+), 13 deletions(-)
Thanks!
| |