[PATCH v3 0/2] sched/fair: Wake task within the cluster when possible

Yicong Yang
2022-06-08T10:15:52Z

This is the follow-up work to support cluster scheduler. Previously
we have added cluster level in the scheduler for both ARM64[1] and
X86[2] to support load balance between clusters to bring more memory
bandwidth and decrease cache contention. This patchset, on the other
hand, takes care of wake-up path by giving CPUs within the same cluster
a try before scanning the whole LLC to benefit those tasks communicating
with each other.

[1] 778c558f49a2 ("sched: Add cluster scheduler level in core and related Kconfig for ARM64")
[2] 66558b730f25 ("sched: Add cluster scheduler level for x86")

Change since v2:
- leverage SIS_PROP to suspend redundant scanning when LLC is overloaded
- remove the ping-pong suppression
- address the comment from Tim, thanks.
Link: https://lore.kernel.org/lkml/20220126080947.4529-1-yangyicong@hisilicon.com/

Change since v1:
- regain the performance data based on v5.17-rc1
- rename cpus_share_cluster to cpus_share_resources per Vincent and Gautham, thanks!
Link: https://lore.kernel.org/lkml/20211215041149.73171-1-yangyicong@hisilicon.com/

Barry Song (2):
sched: Add per_cpu cluster domain info and cpus_share_resources API
sched/fair: Scan cluster before scanning LLC in wake-up path

include/linux/sched/sd_flags.h | 7 ++++++
include/linux/sched/topology.h | 8 ++++++-
kernel/sched/core.c | 12 ++++++++++
kernel/sched/fair.c | 43 +++++++++++++++++++++++++++++++---
kernel/sched/sched.h | 2 ++
kernel/sched/topology.c | 15 ++++++++++++
6 files changed, 83 insertions(+), 4 deletions(-)

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2.24.0