tools/sched_ext: scx_qmap: Restart on hotplug instead of cpu_online/offline

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The cid mapping is built from the online cpu set at scheduler enable
and stays valid for that set; routine hotplug invalidates it. The
default cid behavior is to restart the scheduler so the mapping gets
rebuilt against the new online set, and that requires not implementing
cpu_online / cpu_offline (which suppress the kernel's ACT_RESTART).

Drop the two ops along with their print_cpus() helper - the cluster
view was only useful as a hotplug demo and is meaningless over the
dense cid space the scheduler will move to. Wire main() to handle the
ACT_RESTART exit by reopening the skel and reattaching, matching the
pattern in scx_simple / scx_central / scx_flatcg etc. Reset optind so
getopt re-parses argv into the fresh skel rodata each iteration.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Reviewed-by: Changwoo Min <changwoo@igalia.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>

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This commit is contained in:

Tejun Heo 2026-04-29 08:09:11 -10:00

parent 67edfa9eef

commit 89ddcc0bfd

2 changed files with 7 additions and 68 deletions

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62

tools/sched_ext/scx_qmap.bpf.c

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tools/sched_ext/scx_qmap.c

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