[RFC PATCH v2 0/4] Introduce group balancer

[Tianchen Ding <dtcccc@linux.alibaba.com>]

Modern platform are growing fast on CPU numbers. To achieve better
utility of CPU resource, multiple apps are starting to sharing the CPUs.

What we need is a way to ease confliction in share mode,
make groups as exclusive as possible, to gain both performance
and resource efficiency.

The main idea of group balancer is to fulfill this requirement
by balancing groups of tasks among groups of CPUs, consider this
as a dynamic demi-exclusive mode. Task trigger work to settle it's
group into a proper partition (minimum predicted load), then try
migrate itself into it. To gradually settle groups into the most
exclusively partition.

GB can be seen as an optimize policy based on load balance,
it obeys the main idea of load balance and makes adjustment
based on that.

Our test on ARM64 platform with 128 CPUs shows that,
throughput of sysbench memory is improved about 25%,
and redis-benchmark is improved up to about 10%.

See each patch for detail:
The 1st patch introduces infrastructure.
The 2nd patch introduces detail about partition info.
The 3rd patch is the main part of group balancer.
The 4th patch is about stats.

v2:
Put partition info and period settings to cpuset subsys of cgroup_v2.

v1: https://lore.kernel.org/all/98f41efd-74b2-198a-839c-51b785b748a6@linux.alibaba.com/

Michael Wang (1):
  sched: Introduce group balancer

Tianchen Ding (3):
  sched, cpuset: Introduce infrastructure of group balancer
  cpuset: Handle input of partition info for group balancer
  cpuset, gb: Add stat for group balancer

 include/linux/cpuset.h   |   5 +
 include/linux/sched.h    |   5 +
 include/linux/sched/gb.h |  70 ++++++
 init/Kconfig             |  12 +
 kernel/cgroup/cpuset.c   | 405 +++++++++++++++++++++++++++++++-
 kernel/sched/Makefile    |   1 +
 kernel/sched/core.c      |   5 +
 kernel/sched/debug.c     |  10 +-
 kernel/sched/fair.c      |  26 ++-
 kernel/sched/gb.c        | 487 +++++++++++++++++++++++++++++++++++++++
 kernel/sched/sched.h     |  14 ++
 11 files changed, 1037 insertions(+), 3 deletions(-)
 create mode 100644 include/linux/sched/gb.h
 create mode 100644 kernel/sched/gb.c

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2.27.0