linux/kernel/sched
Tejun Heo 337ec00b1d sched_ext: Implement cgroup sub-sched enabling and disabling
The preceding changes implemented the framework to support cgroup
sub-scheds and updated scheduling paths and kfuncs so that they have
minimal but working support for sub-scheds. However, actual sub-sched
enabling/disabling hasn't been implemented yet and all tasks stayed on
scx_root.

Implement cgroup sub-sched enabling and disabling to actually activate
sub-scheds:

- Both enable and disable operations bypass only the tasks in the subtree
  of the child being enabled or disabled to limit disruptions.

- When enabling, all candidate tasks are first initialized for the child
  sched. Once that succeeds, the tasks are exited for the parent and then
  switched over to the child. This adds a bit of complication but
  guarantees that child scheduler failures are always contained.

- Disabling works the same way in the other direction. However, when the
  parent may fail to initialize a task, disabling is propagated up to the
  parent. While this means that a parent sched fail due to a child sched
  event, the failure can only originate from the parent itself (its
  ops.init_task()). The only effect a malfunctioning child can have on the
  parent is attempting to move the tasks back to the parent.

After this change, although not all the necessary mechanisms are in place
yet, sub-scheds can take control of their tasks and schedule them.

v2: Fix missing scx_cgroup_unlock()/percpu_up_write() in abort path
    (Cheng-Yang Chou).

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-03-06 07:58:04 -10:00
..
autogroup.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
autogroup.h sched: Clean up and standardize #if/#else/#endif markers in sched/autogroup.[ch] 2025-06-13 08:47:14 +02:00
build_policy.c sched_ext: Move internal type and accessor definitions to ext_internal.h 2025-09-03 11:33:28 -10:00
build_utility.c sched/smp: Make SMP unconditional 2025-06-13 08:47:18 +02:00
clock.c sched/clock: Avoid false sharing for sched_clock_irqtime 2026-02-03 12:04:19 +01:00
completion.c sched: Make clangd usable 2025-06-11 11:20:53 +02:00
core_sched.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
core.c sched_ext: Add @kargs to scx_fork() 2026-03-06 07:58:02 -10:00
cpuacct.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
cpudeadline.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
cpudeadline.h sched/deadline: only set free_cpus for online runqueues 2025-10-16 11:13:49 +02:00
cpufreq_schedutil.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
cpufreq.c sched: Make clangd usable 2025-06-11 11:20:53 +02:00
cpupri.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
cpupri.h sched/smp: Make SMP unconditional 2025-06-13 08:47:18 +02:00
cputime.c - A nice cleanup to the paravirt code containing a unification of the paravirt 2026-02-10 19:01:45 -08:00
deadline.c sched/debug: Fix dl_server (re)start conditions 2026-02-03 12:04:18 +01:00
debug.c sched/debug: Fix dl_server (re)start conditions 2026-02-03 12:04:18 +01:00
ext_idle.c sched_ext: Move bypass state into scx_sched 2026-03-06 07:58:03 -10:00
ext_idle.h sched_ext: Always use SMP versions in kernel/sched/ext_idle.h 2025-06-13 14:47:59 -10:00
ext_internal.h sched_ext: Make watchdog sub-sched aware 2026-03-06 07:58:04 -10:00
ext.c sched_ext: Implement cgroup sub-sched enabling and disabling 2026-03-06 07:58:04 -10:00
ext.h sched_ext: Add @kargs to scx_fork() 2026-03-06 07:58:02 -10:00
fair.c sched/core: Fix wakeup_preempt's next_class tracking 2026-02-23 11:19:19 +01:00
features.h sched/fair: Disable scheduler feature NEXT_BUDDY 2026-01-23 11:53:19 +01:00
idle.c sched_ext: Add a DL server for sched_ext tasks 2026-02-03 12:04:17 +01:00
isolation.c cgroup/cpuset: Call housekeeping_update() without holding cpus_read_lock 2026-02-23 10:46:49 -10:00
loadavg.c Merge branch 'tip/sched/urgent' 2025-07-14 17:16:28 +02:00
Makefile sched: Enable context analysis for core.c and fair.c 2026-01-05 16:43:36 +01:00
membarrier.c rseq: Simplify the event notification 2025-11-04 08:30:09 +01:00
pelt.c treewide: Update email address 2026-01-11 06:09:11 -10:00
pelt.h sched/fair: Switch to task based throttle model 2025-09-03 10:03:14 +02:00
psi.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
rq-offsets.c sched: Make migrate_{en,dis}able() inline 2025-09-25 09:57:16 +02:00
rt.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
sched-pelt.h sched: Make clangd usable 2025-06-11 11:20:53 +02:00
sched.h sched_ext: Move bypass state into scx_sched 2026-03-06 07:58:03 -10:00
smp.h sched: Make clangd usable 2025-06-11 11:20:53 +02:00
stats.c sched/smp: Use the SMP version of schedstats 2025-06-13 08:47:21 +02:00
stats.h delayacct: add timestamp of delay max 2026-01-31 16:16:06 -08:00
stop_task.c sched/core: Rework sched_class::wakeup_preempt() and rq_modified_*() 2025-12-17 10:53:25 +01:00
swait.c sched: Make clangd usable 2025-06-11 11:20:53 +02:00
syscalls.c sched: Deadline has dynamic priority 2026-01-15 21:57:53 +01:00
topology.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
wait_bit.c sched: Make clangd usable 2025-06-11 11:20:53 +02:00
wait.c ARM: 2025-07-30 17:14:01 -07:00