[PATCH 0/2] Adjust NUMA imbalance for multiple LLCs

From: Mel Gorman
Date: Thu Nov 25 2021 - 10:21:57 EST


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 use of scheduler domain
weights and sub-optimal performance when there are many LLCs per NUMA node.

include/linux/sched/topology.h | 1 +
kernel/sched/fair.c | 26 +++++++++++++++-----------
kernel/sched/topology.c | 24 ++++++++++++++++++++++++
3 files changed, 40 insertions(+), 11 deletions(-)

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2.31.1