Hi, Peter, Ingo

Could you give some comments please?

As Mel replied previously, he won't disagree the idea, so we're looking
forward the opinion from the maintainers.

Please allow me to highlight the necessary of monitoring NUMA Balancing
again, this feature is critical to the performance on NUMA platform,
it cost and benefit -- lot or less, however there are not enough
information for an admin to analysis the trade-off, while locality could
be the missing piece.

Regards,
Michael Wang

On 2020/1/21 上午9:56, 王贇 wrote:

v8:
  * document edited
v7:
  * rebased on latest linux-next
v6:
  * fix compile failure when NUMA disabled
v5:
  * improved documentation
v4:
  * fix comments and improved documentation
v3:
  * simplified the locality concept & implementation
v2:
  * improved documentation

Modern production environment could use hundreds of cgroup to control
the resources for different workloads, along with the complicated
resource binding.

On NUMA platforms where we have multiple nodes, things become even more
complicated, we hope there are more local memory access to improve the
performance, and NUMA Balancing keep working hard to achieve that,
however, wrong memory policy or node binding could easily waste the
effort, result a lot of remote page accessing.

We need to notice such problems, then we got chance to fix it before
there are too much damages, however, there are no good monitoring
approach yet to help catch the mouse who introduced the remote access.

This patch set is trying to fill in the missing pieces， by introduce
the per-cgroup NUMA locality info, with this new statistics, we could
achieve the daily monitoring on NUMA efficiency, to give warning when
things going too wrong.

Please check the second patch for more details.

Michael Wang (2):
  sched/numa: introduce per-cgroup NUMA locality info
  sched/numa: documentation for per-cgroup numa statistics

 Documentation/admin-guide/cg-numa-stat.rst      | 178 ++++++++++++++++++++++++
 Documentation/admin-guide/index.rst             |   1 +
 Documentation/admin-guide/kernel-parameters.txt |   4 +
 Documentation/admin-guide/sysctl/kernel.rst     |   9 ++
 include/linux/sched.h                           |  15 ++
 include/linux/sched/sysctl.h                    |   6 +
 init/Kconfig                                    |  11 ++
 kernel/sched/core.c                             |  75 ++++++++++
 kernel/sched/fair.c                             |  62 +++++++++
 kernel/sched/sched.h                            |  12 ++
 kernel/sysctl.c                                 |  11 ++
 11 files changed, 384 insertions(+)
 create mode 100644 Documentation/admin-guide/cg-numa-stat.rst