[PATCH 0/2] sched: Address idle task vs pcpu kthread checks

From: Valentin Schneider
Date: Mon May 10 2021 - 11:11:46 EST


Commit

5ba2ffba13a1 ("sched: Fix CPU hotplug / tighten is_per_cpu_kthread()")

had to special-case the idle task when checking for per-CPU kthreads. This is
due to the idle task not having its own struct kthread, which is where we'd
store KTHREAD_IS_PER_CPU.

>From staring at Yejune's recent patch [1], it turns out the idle task is also
missing PF_NO_SETAFFINITY.

Patch 1 cleans this up, patch 2 is Yejune's v1 which depends on it.


Note: I remember seeing some patch(es) from Peter tackling this exact
problem, but I couldn't find them again.

[1]: http://lore.kernel.org/r/1620458722-13026-1-git-send-email-yejunedeng@xxxxxxxxx

Cheers,
Valentin

Valentin Schneider (1):
sched: Make the idle task quack like a per-CPU kthread

Yejune Deng (1):
lib/smp_processor_id: Use is_percpu_thread() instead of
nr_cpus_allowed

include/linux/kthread.h | 2 ++
kernel/kthread.c | 30 ++++++++++++++++++------------
kernel/sched/core.c | 21 +++++++++++++++------
lib/smp_processor_id.c | 6 +-----
4 files changed, 36 insertions(+), 23 deletions(-)

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2.25.1