On Thu, 2005-12-22 at 18:56 +1100, Nick Piggin wrote:
Ingo Molnar wrote:
* Nick Piggin <nickpiggin@xxxxxxxxxxxx> wrote:
It would be nice to first do a run with a fair implementation of mutexes.
which fairness implementation do you mean - the one where all tasks will get the lock in fair FIFO order, and a 'lucky bastard' cannot steal the lock from waiters and thus put them at an indefinite disadvantage?
I guess so. I'm not so worried about the rare 'lucky bastard' ie. a
lock request coming in concurrently, but rather the naturally favoured
'this CPU' taking the lock again after waking up the head waiter but
before it gets a chance to run / transfer the cacheline.
that's just the most evil lucky bastard....