Re: [PATCH V1] fuse: give wakeup hints to the scheduler

[Peter Zijlstra]

On Tue, Dec 07, 2021 at 02:45:49PM +0100, Peter Zijlstra wrote:

> > What would be much nicer, is to look at all the threads on the waitq
> > and pick one that previously ran on the current CPU if there's one.
> > Could this be implemented?
> 
> It would violate the FIFO semantics of _exclusive.

That said, look at
kernel/locking/percpu-rwsem.c:percpu_rwsem_wake_function() for how to do
really terrible things with waitqueues, possibly including what you
suggest.