[GIT PULL] sched_ext: Initial pull request for v6.11

[Tejun Heo <tj@kernel.org>]

NOTE: I couldn't get git-request-pull to generate the correct diffstat. The
      diffstat at the end is generated against the merged base and should
      match the diff when sched_ext-for-6.11 is pulled after tip/sched/core
      and bpf/for-next.

The following changes since commit d329605287020c3d1c3b0dadc63d8208e7251382:

  sched/fair: set_load_weight() must also call reweight_task() for SCHED_IDLE tasks (2024-07-04 15:59:52 +0200)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext.git/ tags/sched_ext-for-6.11

for you to fetch changes up to 8bb30798fd6ee79e4041a32ca85b9f70345d8671:

  sched_ext: Fixes incorrect type in bpf_scx_init() (2024-07-14 18:10:10 -1000)

----------------------------------------------------------------
sched_ext: Initial pull request for v6.11

This is the initial pull request of sched_ext. The v7 patchset
(https://lkml.kernel.org/r/20240618212056.2833381-1-tj@kernel.org) is
applied on top of tip/sched/core + bpf/for-next as of Jun 18th.

  tip/sched/core 793a62823d1c ("sched/core: Drop spinlocks on contention iff kernel is preemptible")
  bpf/for-next   f6afdaf72af7 ("Merge branch 'bpf-support-resilient-split-btf'")

Since then, the following changes:

- cpuperf support which was a part of the v6 patchset was posted separately
  and then applied after reviews.

- tip/sched/core is pulled into resolve the conflicts between

    e83edbf88f18 ("sched: Add sched_class->reweight_task()")
    d32960528702 ("sched/fair: set_load_weight() must also call reweight_task() for SCHED_IDLE tasks")

  The former makes reweight_task() a sched_class operation for sched_ext
  while the latter fixed a bug around idle weight handling in the same area.
  The conflicts are not trivial although not that complicated either.

- Improve integration with sched core.

- DSQ iterator which was a part of the v6 patchset was posted separately.
  The iterator itself was applied after a couple revisions. The associated
  selective consumption kfunc can use further improvements and is still
  being worked on.

- The BPF scheduler couldn't directly dispatch to the local DSQ of another
  CPU using a SCX_DSQ_LOCAL_ON verdict. This caused difficulties around
  handling non-wakeup enqueues. Updated so that SCX_DSQ_LOCAL_ON can be used
  in the enqueue path too.

- Various fixes and improvements.

As the branch is based on top of tip/sched/core + bpf/for-next, please merge
after both are applied.

----------------------------------------------------------------
Aboorva Devarajan (1):
      sched_ext: Documentation: Remove mentions of scx_bpf_switch_all

Andrea Righi (2):
      sched_ext: fix typo in set_weight() description
      sched_ext: add CONFIG_DEBUG_INFO_BTF dependency

Colin Ian King (1):
      sched_ext: Fix spelling mistake: "intead" -> "instead"

David Vernet (6):
      sched_ext: Implement runnable task stall watchdog
      sched_ext: Print sched_ext info when dumping stack
      sched_ext: Implement SCX_KICK_WAIT
      sched_ext: Implement sched_ext_ops.cpu_acquire/release()
      sched_ext: Add selftests
      sched_ext: Make scx_bpf_cpuperf_set() @cpu arg signed

Hongyan Xia (1):
      sched/ext: Add BPF function to fetch rq

Jiapeng Chong (1):
      sched_ext: Fixes incorrect type in bpf_scx_init()

Tejun Heo (48):
      sched: Restructure sched_class order sanity checks in sched_init()
      sched: Allow sched_cgroup_fork() to fail and introduce sched_cancel_fork()
      sched: Add sched_class->reweight_task()
      sched: Add sched_class->switching_to() and expose check_class_changing/changed()
      sched: Factor out cgroup weight conversion functions
      sched: Factor out update_other_load_avgs() from __update_blocked_others()
      sched: Add normal_policy()
      sched_ext: Add boilerplate for extensible scheduler class
      sched_ext: Implement BPF extensible scheduler class
      sched_ext: Add scx_simple and scx_example_qmap example schedulers
      sched_ext: Add sysrq-S which disables the BPF scheduler
      sched_ext: Allow BPF schedulers to disallow specific tasks from joining SCHED_EXT
      sched_ext: Print debug dump after an error exit
      tools/sched_ext: Add scx_show_state.py
      sched_ext: Implement scx_bpf_kick_cpu() and task preemption support
      sched_ext: Add a central scheduler which makes all scheduling decisions on one CPU
      sched_ext: Make watchdog handle ops.dispatch() looping stall
      sched_ext: Add task state tracking operations
      sched_ext: Implement tickless support
      sched_ext: Track tasks that are subjects of the in-flight SCX operation
      sched_ext: Implement sched_ext_ops.cpu_online/offline()
      sched_ext: Bypass BPF scheduler while PM events are in progress
      sched_ext: Implement core-sched support
      sched_ext: Add vtime-ordered priority queue to dispatch_q's
      sched_ext: Documentation: scheduler: Document extensible scheduler class
      sched, sched_ext: Replace scx_next_task_picked() with sched_class->switch_class()
      cpufreq_schedutil: Refactor sugov_cpu_is_busy()
      sched_ext: Add cpuperf support
      sched_ext: Drop tools_clean target from the top-level Makefile
      sched_ext: Swap argument positions in kcalloc() call to avoid compiler warning
      Merge branch 'sched/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into for-6.11
      sched, sched_ext: Simplify dl_prio() case handling in sched_fork()
      sched_ext: Account for idle policy when setting p->scx.weight in scx_ops_enable_task()
      sched_ext: Disallow loading BPF scheduler if isolcpus= domain isolation is in effect
      sched_ext: Minor cleanups in kernel/sched/ext.h
      sched, sched_ext: Open code for_balance_class_range()
      sched, sched_ext: Move some declarations from kernel/sched/ext.h to sched.h
      sched_ext: Take out ->priq and ->flags from scx_dsq_node
      sched_ext: Implement DSQ iterator
      sched_ext/scx_qmap: Add an example usage of DSQ iterator
      sched_ext: Reimplement scx_bpf_reenqueue_local()
      sched_ext: Make scx_bpf_reenqueue_local() skip tasks that are being migrated
      sched: Move struct balance_callback definition upward
      sched_ext: Open-code task_linked_on_dsq()
      sched_ext: Unpin and repin rq lock from balance_scx()
      sched_ext: s/SCX_RQ_BALANCING/SCX_RQ_IN_BALANCE/ and add SCX_RQ_IN_WAKEUP
      sched_ext: Allow SCX_DSQ_LOCAL_ON for direct dispatches
      sched_ext/scx_qmap: Pick idle CPU for direct dispatch on !wakeup enqueues

 Documentation/scheduler/index.rst                                   |    1
 Documentation/scheduler/sched-ext.rst                               |  316 +
 MAINTAINERS                                                         |   13
 drivers/tty/sysrq.c                                                 |    1
 include/asm-generic/vmlinux.lds.h                                   |    1
 include/linux/cgroup.h                                              |    4
 include/linux/sched.h                                               |    5
 include/linux/sched/ext.h                                           |  206
 include/linux/sched/task.h                                          |    3
 include/trace/events/sched_ext.h                                    |   32
 include/uapi/linux/sched.h                                          |    1
 init/init_task.c                                                    |   12
 kernel/Kconfig.preempt                                              |   26
 kernel/fork.c                                                       |   17
 kernel/sched/build_policy.c                                         |   11
 kernel/sched/core.c                                                 |  192
 kernel/sched/cpufreq_schedutil.c                                    |   50
 kernel/sched/debug.c                                                |    3
 kernel/sched/ext.c                                                  | 6537 ++++++++++++++++++++++++++
 kernel/sched/ext.h                                                  |   69
 kernel/sched/fair.c                                                 |   22
 kernel/sched/idle.c                                                 |    2
 kernel/sched/sched.h                                                |  158
 kernel/sched/syscalls.c                                             |   26
 lib/dump_stack.c                                                    |    1
 tools/Makefile                                                      |   10
 tools/sched_ext/.gitignore                                          |    2
 tools/sched_ext/Makefile                                            |  246
 tools/sched_ext/README.md                                           |  258 +
 tools/sched_ext/include/bpf-compat/gnu/stubs.h                      |   11
 tools/sched_ext/include/scx/common.bpf.h                            |  401 +
 tools/sched_ext/include/scx/common.h                                |   75
 tools/sched_ext/include/scx/compat.bpf.h                            |   28
 tools/sched_ext/include/scx/compat.h                                |  186
 tools/sched_ext/include/scx/user_exit_info.h                        |  111
 tools/sched_ext/scx_central.bpf.c                                   |  361 +
 tools/sched_ext/scx_central.c                                       |  135
 tools/sched_ext/scx_qmap.bpf.c                                      |  706 ++
 tools/sched_ext/scx_qmap.c                                          |  144
 tools/sched_ext/scx_show_state.py                                   |   39
 tools/sched_ext/scx_simple.bpf.c                                    |  156
 tools/sched_ext/scx_simple.c                                        |  107
 tools/testing/selftests/sched_ext/.gitignore                        |    6
 tools/testing/selftests/sched_ext/Makefile                          |  218
 tools/testing/selftests/sched_ext/config                            |    9
 tools/testing/selftests/sched_ext/create_dsq.bpf.c                  |   58
 tools/testing/selftests/sched_ext/create_dsq.c                      |   57
 tools/testing/selftests/sched_ext/ddsp_bogus_dsq_fail.bpf.c         |   42
 tools/testing/selftests/sched_ext/ddsp_bogus_dsq_fail.c             |   57
 tools/testing/selftests/sched_ext/ddsp_vtimelocal_fail.bpf.c        |   39
 tools/testing/selftests/sched_ext/ddsp_vtimelocal_fail.c            |   56
 tools/testing/selftests/sched_ext/dsp_local_on.bpf.c                |   65
 tools/testing/selftests/sched_ext/dsp_local_on.c                    |   58
 tools/testing/selftests/sched_ext/enq_last_no_enq_fails.bpf.c       |   21
 tools/testing/selftests/sched_ext/enq_last_no_enq_fails.c           |   60
 tools/testing/selftests/sched_ext/enq_select_cpu_fails.bpf.c        |   43
 tools/testing/selftests/sched_ext/enq_select_cpu_fails.c            |   61
 tools/testing/selftests/sched_ext/exit.bpf.c                        |   84
 tools/testing/selftests/sched_ext/exit.c                            |   55
 tools/testing/selftests/sched_ext/exit_test.h                       |   20
 tools/testing/selftests/sched_ext/hotplug.bpf.c                     |   61
 tools/testing/selftests/sched_ext/hotplug.c                         |  168
 tools/testing/selftests/sched_ext/hotplug_test.h                    |   15
 tools/testing/selftests/sched_ext/init_enable_count.bpf.c           |   53
 tools/testing/selftests/sched_ext/init_enable_count.c               |  166
 tools/testing/selftests/sched_ext/maximal.bpf.c                     |  132
 tools/testing/selftests/sched_ext/maximal.c                         |   51
 tools/testing/selftests/sched_ext/maybe_null.bpf.c                  |   36
 tools/testing/selftests/sched_ext/maybe_null.c                      |   49
 tools/testing/selftests/sched_ext/maybe_null_fail_dsp.bpf.c         |   25
 tools/testing/selftests/sched_ext/maybe_null_fail_yld.bpf.c         |   28
 tools/testing/selftests/sched_ext/minimal.bpf.c                     |   21
 tools/testing/selftests/sched_ext/minimal.c                         |   58
 tools/testing/selftests/sched_ext/prog_run.bpf.c                    |   32
 tools/testing/selftests/sched_ext/prog_run.c                        |   78
 tools/testing/selftests/sched_ext/reload_loop.c                     |   75
 tools/testing/selftests/sched_ext/runner.c                          |  201
 tools/testing/selftests/sched_ext/scx_test.h                        |  131
 tools/testing/selftests/sched_ext/select_cpu_dfl.bpf.c              |   40
 tools/testing/selftests/sched_ext/select_cpu_dfl.c                  |   72
 tools/testing/selftests/sched_ext/select_cpu_dfl_nodispatch.bpf.c   |   89
 tools/testing/selftests/sched_ext/select_cpu_dfl_nodispatch.c       |   72
 tools/testing/selftests/sched_ext/select_cpu_dispatch.bpf.c         |   41
 tools/testing/selftests/sched_ext/select_cpu_dispatch.c             |   70
 tools/testing/selftests/sched_ext/select_cpu_dispatch_bad_dsq.bpf.c |   37
 tools/testing/selftests/sched_ext/select_cpu_dispatch_bad_dsq.c     |   56
 tools/testing/selftests/sched_ext/select_cpu_dispatch_dbl_dsp.bpf.c |   38
 tools/testing/selftests/sched_ext/select_cpu_dispatch_dbl_dsp.c     |   56
 tools/testing/selftests/sched_ext/select_cpu_vtime.bpf.c            |   92
 tools/testing/selftests/sched_ext/select_cpu_vtime.c                |   59
 tools/testing/selftests/sched_ext/test_example.c                    |   49
 tools/testing/selftests/sched_ext/util.c                            |   71
 tools/testing/selftests/sched_ext/util.h                            |   13
 93 files changed, 13834 insertions(+), 95 deletions(-)