linux/include
Tejun Heo a6ec0b62c5 sched_ext: Hand over cgroups at sub-scheduler enable/disable
Sub-schedulers don't get cgroups yet: every task_group is inited on the root
sched and the routing added by the previous patches always resolves to it.
Add the handover: an enabling sub-scheduler takes over the cgroups in its
subtree and a disabling one returns them to its parent.

scx_cgroup_claim_subtree() runs while the sub enables, after the subtree's
cgrp->scx_sched's are set and before any task is claimed. It inits each
subtree task_group on the sub, exits it from the parent and updates
tg->scx.sched. A failed ops.cgroup_init() unwinds the sub-side inits and
aborts the enable with the parent untouched.

Disabling reverses it with scx_cgroup_return_subtree(): exit each cgroup
from the sub, then re-init it on the parent with the current tg->scx.*
values, resyncing weight and bandwidth changes made while the sub had it.
When a re-init fails, the parent is failed and the remaining task_groups
still transfer uninited and get no cgroup ops - the same punting done for
tasks. The dying parent's own disable moves them onward.

The handover walks include dying but not yet offlined task_groups, the same
as root's bulk walks: a removed cgroup keeps hosting scheduling events until
its dying tasks finish their final context switches, and its
ops.cgroup_exit() must follow the last of them. tg on/offlining is excluded
through cgroup_lock(), so either ordering against an rmdir of a subtree
cgroup delivers balanced init/exit pairs.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-07-19 21:10:57 -10:00
..
acpi Driver core changes for 7.2-rc1 2026-06-15 12:41:17 +05:30
asm-generic mm.git review status for mm-hotfixes-stable..mm-nonmm-stable 2026-06-21 13:20:19 -07:00
clocksource
crypto Networking changes for 7.2. 2026-06-17 08:17:00 +01:00
cxl cxl/region: Introduce devm_cxl_probe_mem() 2026-06-12 13:47:30 -07:00
drm drm-next for 7.2-rc1 2026-06-17 10:21:00 +01:00
dt-bindings Char/Misc/IIO/FPGA/GPIB/etc driver updates for 7.2-rc1 2026-06-22 12:20:21 -07:00
hyperv
keys keys: Pin request_key_auth payload in instantiate paths 2026-06-15 15:19:13 +03:00
kunit linux_kselftest-kunit-7.2-rc1 2026-06-16 16:33:57 +05:30
kvm Merge branch kvm-arm64/vgic-v5-PPI-fixes into kvmarm-master/next 2026-06-12 09:08:31 +01:00
linux sched_ext: Hand over cgroups at sub-scheduler enable/disable 2026-07-19 21:10:57 -10:00
math-emu
media
memory
misc
net Asides of the avalanche of LLM-driven fixes, there are a couple of 2026-06-21 10:26:31 -07:00
pcmcia
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rdma RDMA v7.2 merge window 2026-06-18 08:16:21 -07:00
rv
scsi
soc phy-for-7.2 2026-06-23 15:41:48 -07:00
sound ASoC: Updates for v7.2 2026-06-15 20:19:22 +02:00
target
trace sched_ext: Add tracepoint for scheduler exit 2026-07-10 06:25:24 -10:00
uapi Char/Misc/IIO/FPGA/GPIB/etc driver updates for 7.2-rc1 2026-06-22 12:20:21 -07:00
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vdso
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xen xen: constify xsd_errors array 2026-06-08 09:00:06 +02:00
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