[GIT PULL] scheduler updates for v5.13

[Ingo Molnar]

Linus,

Please pull the latest sched/core git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched-core-2021-04-28

   # HEAD: 2ea46c6fc9452ac100ad907b051d797225847e33 cpumask/hotplug: Fix cpu_dying() state tracking

Scheduler updates for this cycle are:

 - Clean up SCHED_DEBUG: move the decades old mess of sysctl, procfs and debugfs interfaces
   to a unified debugfs interface.

 - Signals: Allow caching one sigqueue object per task, to improve performance & latencies.

 - Improve newidle_balance() irq-off latencies on systems with a large number of CPU cgroups.

 - Improve energy-aware scheduling

 - Improve the PELT metrics for certain workloads

 - Reintroduce select_idle_smt() to improve load-balancing locality - but without the previous
   regressions

 - Add 'scheduler latency debugging': warn after long periods of pending need_resched. This
   is an opt-in feature that requires the enabling of the LATENCY_WARN scheduler feature,
   or the use of the resched_latency_warn_ms=xx boot parameter.

 - CPU hotplug fixes for HP-rollback, and for the 'fail' interface. Fix remaining
   balance_push() vs. hotplug holes/races

 - PSI fixes, plus allow /proc/pressure/ files to be written by CAP_SYS_RESOURCE tasks as well

 - Fix/improve various load-balancing corner cases vs. capacity margins

 - Fix sched topology on systems with NUMA diameter of 3 or above

 - Fix PF_KTHREAD vs to_kthread() race

 - Minor rseq optimizations

 - Misc cleanups, optimizations, fixes and smaller updates

 Thanks,

	Ingo

------------------>
Aubrey Li (1):
      sched/fair: Reduce long-tail newly idle balance cost

Barry Song (3):
      sched/topology: fix the issue groups don't span domain->span for NUMA diameter > 2
      sched/fair: Optimize test_idle_cores() for !SMT
      sched/topology: Remove redundant cpumask_and() in init_overlap_sched_group()

Charan Teja Reddy (1):
      sched,psi: Handle potential task count underflow bugs more gracefully

Chengming Zhou (3):
      psi: Add PSI_CPU_FULL state
      psi: Use ONCPU state tracking machinery to detect reclaim
      psi: Optimize task switch inside shared cgroups

Clement Courbet (1):
      sched: Optimize __calc_delta()

Edmundo Carmona Antoranz (1):
      sched: Remove unnecessary variable from schedule_tail()

Eric Dumazet (3):
      rseq: Optimize rseq_update_cpu_id()
      rseq: Remove redundant access_ok()
      rseq: Optimise rseq_get_rseq_cs() and clear_rseq_cs()

Ingo Molnar (1):
      sched: Fix various typos

Johannes Weiner (1):
      psi: Pressure states are unlikely

Josh Hunt (1):
      psi: allow unprivileged users with CAP_SYS_RESOURCE to write psi files

Lingutla Chandrasekhar (1):
      sched/fair: Ignore percpu threads for imbalance pulls

Mel Gorman (1):
      sched/numa: Allow runtime enabling/disabling of NUMA balance without SCHED_DEBUG

Paul Turner (1):
      sched: Warn on long periods of pending need_resched

Peter Zijlstra (14):
      cpumask: Make cpu_{online,possible,present,active}() inline
      cpumask: Introduce DYING mask
      sched: Use cpu_dying() to fix balance_push vs hotplug-rollback
      sched: Remove sched_schedstats sysctl out from under SCHED_DEBUG
      sched: Don't make LATENCYTOP select SCHED_DEBUG
      sched: Move SCHED_DEBUG sysctl to debugfs
      sched,preempt: Move preempt_dynamic to debug.c
      debugfs: Implement debugfs_create_str()
      sched,debug: Convert sysctl sched_domains to debugfs
      sched: Move /proc/sched_debug to debugfs
      sched,fair: Alternative sched_slice()
      sched/debug: Rename the sched_debug parameter to sched_verbose
      kthread: Fix PF_KTHREAD vs to_kthread() race
      cpumask/hotplug: Fix cpu_dying() state tracking

Piotr Figiel (1):
      rseq, ptrace: Add PTRACE_GET_RSEQ_CONFIGURATION request

Rasmus Villemoes (2):
      sched/core: Stop using magic values in sched_dynamic_mode()
      sched/core: Use -EINVAL in sched_dynamic_mode()

Rik van Riel (1):
      sched/fair: Bring back select_idle_smt(), but differently

Sebastian Andrzej Siewior (1):
      kcov: Remove kcov include from sched.h and move it to its users.

Shakeel Butt (1):
      psi: Reduce calls to sched_clock() in psi

Thomas Gleixner (2):
      signal: Hand SIGQUEUE_PREALLOC flag to __sigqueue_alloc()
      signal: Allow tasks to cache one sigqueue struct

Valentin Schneider (5):
      sched: Simplify migration_cpu_stop()
      sched/fair: Fix shift-out-of-bounds in load_balance()
      stop_machine: Add caller debug info to queue_stop_cpus_work
      sched/fair: Clean up active balance nr_balance_failed trickery
      sched/fair: Introduce a CPU capacity comparison helper

Vincent Donnefort (6):
      sched/fair: Fix task utilization accountability in compute_energy()
      sched/fair: use lsub_positive in cpu_util_next()
      sched/pelt: Fix task util_est update filtering
      cpu/hotplug: Allowing to reset fail injection
      cpu/hotplug: CPUHP_BRINGUP_CPU failure exception
      cpu/hotplug: Add cpuhp_invoke_callback_range()

Vincent Guittot (7):
      sched/fair: Remove update of blocked load from newidle_balance
      sched/fair: Remove unused return of _nohz_idle_balance
      sched/fair: Remove unused parameter of update_nohz_stats
      sched/fair: Merge for each idle cpu loop of ILB
      sched/fair: Reorder newidle_balance pulled_task tests
      sched/fair: Trigger the update of blocked load on newly idle cpu
      sched/fair: Reduce the window for duplicated update

Waiman Long (1):
      sched/debug: Fix cgroup_path[] serialization

YueHaibing (1):
      sched/fair: Move update_nohz_stats() to the CONFIG_NO_HZ_COMMON block to simplify the code & fix an unused function warning


 Documentation/admin-guide/kernel-parameters.txt |   2 +-
 Documentation/scheduler/sched-domains.rst       |  10 +-
 drivers/usb/usbip/usbip_common.h                |   1 +
 fs/debugfs/file.c                               |  91 +++++
 include/linux/cpumask.h                         | 117 +++++--
 include/linux/debugfs.h                         |  17 +
 include/linux/kcov.h                            |   1 +
 include/linux/psi.h                             |   1 -
 include/linux/psi_types.h                       |   3 +-
 include/linux/sched.h                           |   4 +-
 include/linux/sched/sysctl.h                    |   9 +-
 include/linux/signal.h                          |   1 +
 include/uapi/linux/ptrace.h                     |  10 +
 kernel/cpu.c                                    | 210 ++++++++----
 kernel/exit.c                                   |   1 +
 kernel/fork.c                                   |   1 +
 kernel/kthread.c                                |  33 +-
 kernel/ptrace.c                                 |  25 ++
 kernel/rseq.c                                   |  29 +-
 kernel/sched/clock.c                            |   2 +-
 kernel/sched/core.c                             | 217 ++++++------
 kernel/sched/cpuacct.c                          |   2 +-
 kernel/sched/cpufreq_schedutil.c                |   2 +-
 kernel/sched/cpupri.c                           |   4 +-
 kernel/sched/cputime.c                          |   2 +-
 kernel/sched/deadline.c                         |  12 +-
 kernel/sched/debug.c                            | 435 +++++++++++++-----------
 kernel/sched/fair.c                             | 380 +++++++++++----------
 kernel/sched/features.h                         |   7 +-
 kernel/sched/idle.c                             |  10 +-
 kernel/sched/loadavg.c                          |   2 +-
 kernel/sched/pelt.c                             |   2 +-
 kernel/sched/pelt.h                             |   2 +-
 kernel/sched/psi.c                              | 164 +++++----
 kernel/sched/rt.c                               |   6 +-
 kernel/sched/sched.h                            |  59 +++-
 kernel/sched/stats.c                            |   2 +-
 kernel/sched/stats.h                            |  37 +-
 kernel/sched/topology.c                         | 113 +++---
 kernel/signal.c                                 |  59 +++-
 kernel/stop_machine.c                           |   1 +
 kernel/sysctl.c                                 |  94 -----
 lib/Kconfig.debug                               |   1 -
 net/core/skbuff.c                               |   1 +
 net/mac80211/iface.c                            |   1 +
 net/mac80211/rx.c                               |   1 +
 46 files changed, 1284 insertions(+), 900 deletions(-)