genirq: Wake interrupt threads immediately when changing affinity

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The affinity setting of interrupt threads happens in the context of the
thread when the thread is woken up by an hard interrupt. As this can be an
arbitrary after changing the affinity, the thread can become runnable on an
isolated CPU and cause isolation disruption.

Avoid this by checking the set affinity request in wait_for_interrupt() and
waking the threads immediately when the affinity is modified.

Note that this is of the most benefit on systems where the interrupt
affinity itself does not need to be deferred to the interrupt handler, but
even where that's not the case, the total dirsuption will be less.

Signed-off-by: Crystal Wood <crwood@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240122235353.15235-1-crwood@redhat.com

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Crystal Wood 2024-01-22 17:53:53 -06:00 • committed by Thomas Gleixner

parent ee4c1592b7

commit c99303a2d2

1 changed files with 55 additions and 54 deletions

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kernel/irq/manage.c

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