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>,
Gautham Shenoy <gautham.shenoy@amd.com>,
K Prateek Nayak <kprateek.nayak@amd.com>,
LKML <linux-kernel@vger.kernel.org>,
Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH v6 0/2] Adjust NUMA imbalance for multiple LLCs
Date: Tue, 8 Feb 2022 09:43:32 +0000 [thread overview]
Message-ID: <20220208094334.16379-1-mgorman@techsingularity.net> (raw)
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(-)
--
2.31.1
next reply other threads:[~2022-02-08 11:24 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-08 9:43 Mel Gorman [this message]
2022-02-08 9:43 ` [PATCH 1/2] sched/fair: Improve consistency of allowed NUMA balance calculations Mel Gorman
2022-02-08 15:06 ` Gautham R. Shenoy
2022-02-14 9:48 ` Vincent Guittot
2022-02-14 10:26 ` Srikar Dronamraju
2022-02-14 10:30 ` [tip: sched/core] " tip-bot2 for Mel Gorman
2022-02-08 9:43 ` [PATCH 2/2] sched/fair: Adjust the allowed NUMA imbalance when SD_NUMA spans multiple LLCs Mel Gorman
2022-02-08 16:19 ` Gautham R. Shenoy
2022-02-09 5:10 ` K Prateek Nayak
2022-02-09 10:33 ` Mel Gorman
2022-02-11 19:02 ` Jirka Hladky
2022-02-14 10:27 ` Srikar Dronamraju
2022-02-14 10:30 ` [tip: sched/core] " tip-bot2 for Mel Gorman
2022-02-14 11:03 ` [PATCH 2/2] " Vincent Guittot
2022-02-09 9:38 ` [PATCH v6 0/2] Adjust NUMA imbalance for " Peter Zijlstra
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