futex: Avoid redundant task lookup

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No need to do the full VPID based task lookup and validation of the top
waiter when the user space futex was acquired on it's behalf during the
requeue_pi operation. The task is known already and it cannot go away
before requeue_pi_wake_futex() has been invoked.

Split out the actual attach code from attach_pi_state_owner() and use that
instead of the full blown variant.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210902094414.676104881@linutronix.de

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Thomas Gleixner 2021-09-02 11:48:51 +02:00

parent 249955e51c

commit 340576590d

1 changed files with 37 additions and 30 deletions

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kernel/futex.c

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