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

From: Mel Gorman <mgorman@techsingularity.net>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Valentin Schneider <valentin.schneider@arm.com>,
	Aubrey Li <aubrey.li@linux.intel.com>,
	Barry Song <song.bao.hua@hisilicon.com>,
	Mike Galbraith <efault@gmx.de>,
	Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH 0/2] Adjust NUMA imbalance for multiple LLCs
Date: Thu, 25 Nov 2021 15:19:39 +0000	[thread overview]
Message-ID: <20211125151941.8710-1-mgorman@techsingularity.net> (raw)

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(-)

-- 
2.31.1