Re: [PATCH 1/7] locking/rwsem: don't resched at the end of optimistic spinning

From
Peter Zijlstra <peterz@infradead.org>
Date
2014-08-04 07:55:41
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Reply to
Waiman Long, 2014-08-04
On Sun, Aug 03, 2014 at 10:36:16PM -0400, Waiman Long wrote:
For a fully preemptive kernel, a call to preempt_enable() could
potentially trigger a task rescheduling event. In the case of rwsem
optimistic spinning, the task has either gotten the lock or is going
to sleep soon. So there is no point to do rescheduling here.
Uh what? Why shouldn't we preempt if we've gotten the lock? What if a
FIFO task just woke up?

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Thread (23 messages) 23 messages, 4 authors, last reply 2014-08-05
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