[PATCH v2 00/19] Fixes for sched/numa_balancing

[Srikar Dronamraju <srikar@linux.vnet.ibm.com>]

This patchset based on v4.17, provides few simple cleanups and fixes in
the sched/numa_balancing code. Some of these fixes are specific to systems
having more than 2 nodes. Few patches add per-rq and per-node complexities
to solve what I feel are a fairness/correctness issues.

This version handles the comments given to some of the patches.
It also provides specjbb2005 numbers on a patch basis on a 4 node and
16 node system.

Running SPECjbb2005 on a 4 node machine and comparing bops/JVM
(higher bops are better)
JVMS  v4.17  	v4.17+patch   %CHANGE
16    25705.2     26158.1     1.731
1     74433	  72725       -2.34

Running SPECjbb2005 on a 16 node machine and comparing bops/JVM
(higher bops are better)
JVMS  v4.17  	v4.17+patch   %CHANGE
8     96589.6     113992      15.26
1     181830      174947      -3.93

Only patches, 2, 4, 13 and 16 have code changes. The rest of the patches are
unchanged.

For overall numbers with v1 running perf-bench please look at
https://lwn.net/ml/linux-kernel/1528106428-19992-1-git-send-email-srikar@linux.vnet.ibm.com

Srikar Dronamraju (19):
  sched/numa: Remove redundant field.
  sched/numa: Evaluate move once per node
  sched/numa: Simplify load_too_imbalanced
  sched/numa: Set preferred_node based on best_cpu
  sched/numa: Use task faults only if numa_group is not yet setup
  sched/debug: Reverse the order of printing faults
  sched/numa: Skip nodes that are at hoplimit
  sched/numa: Remove unused task_capacity from numa_stats
  sched/numa: Modify migrate_swap to accept additional params
  sched/numa: Stop multiple tasks from moving to the cpu at the same time
  sched/numa: Restrict migrating in parallel to the same node.
  sched/numa: Remove numa_has_capacity
  mm/migrate: Use xchg instead of spinlock
  sched/numa: Updation of scan period need not be in lock
  sched/numa: Use group_weights to identify if migration degrades locality
  sched/numa: Detect if node actively handling migration
  sched/numa: Pass destination cpu as a parameter to migrate_task_rq
  sched/numa: Reset scan rate whenever task moves across nodes
  sched/numa: Move task_placement closer to numa_migrate_preferred

 include/linux/mmzone.h  |   4 +-
 include/linux/sched.h   |   1 -
 kernel/sched/core.c     |  11 +-
 kernel/sched/deadline.c |   2 +-
 kernel/sched/debug.c    |   4 +-
 kernel/sched/fair.c     | 325 +++++++++++++++++++++++-------------------------
 kernel/sched/sched.h    |   6 +-
 mm/migrate.c            |  20 ++-
 mm/page_alloc.c         |   2 +-
 9 files changed, 187 insertions(+), 188 deletions(-)

-- 
1.8.3.1