[PATCH v3 0/7] sched: Flatten the pick

[Peter Zijlstra]

Hi!

New version, same story [1]. TL;DR:

 - Adds new cgroup_mode knob and implements new policies to address the
   hierarchy level weight mismatch.

 - Builds upon that base to create a flat / single runqueue scheduler where the
   cgroup hierarchy is expressed through dynamic weight management.

I'm hoping to be able to merge these patches early in the next cycle (after
7.2-rc1).

Random benchmark:

Game vs 'for ((i=0; i<8; i++)) do nice ./spin.sh; done':

  Lutris / GE-Proton10-34 / Steam Runtime 3 (sniper)
  Intel Core i7-2600K
  AMD Radeon RX 580

  Shadows Awakening (GOG)

	  default slice(*)

  FPS min   4.0   29.0
      avg  47.5   59.2
      max  83.7   83.7

  FT  min   9.3   10.2
      avg  34.0   17.0
      max 121.2   30.0

  FPS (Frames Per Second)
  FT  (FrameTime)

  [*] Command prefix: 'chrt -o --sched-runtime 100000 0'


Changes since v2:

 - merged debug and prep patches
 - fixed update_entity_lag() on dequeue (Vincent)
 - fixed throttle vs tick (Prateek)
 - fixed wakeup_preempt_fair()
 - rebased on tip/sched/core
 - rewritten cgroup_mode changelogs
 - reworked cgroup_mode concur
 - added cgroup_mode tasks
 - changed default cgroup_mode


[1] - https://lore.kernel.org/r/20260511113104.563854162@xxxxxxxxxxxxx

Can also be had:

  git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/flat

 include/linux/cpuset.h |    6 
 include/linux/sched.h  |    1 
 kernel/cgroup/cpuset.c |   15 
 kernel/sched/core.c    |    5 
 kernel/sched/debug.c   |   89 ++++
 kernel/sched/fair.c    |  943 ++++++++++++++++++++++++-------------------------
 kernel/sched/pelt.c    |    6 
 kernel/sched/sched.h   |   30 -
 8 files changed, 607 insertions(+), 488 deletions(-)