| Date | Fri, 7 Apr 2017 18:27:07 -0700 | From | Darren Hart <> | Subject | Re: [PATCH -v6 12/13] futex: futex_unlock_pi() determinism |
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On Wed, Mar 22, 2017 at 11:35:59AM +0100, Peter Zijlstra wrote: > The problem with returning -EAGAIN when the waiter state mismatches is > that it becomes very hard to proof a bounded execution time on the
prove
> operation. And seeing that this is a RT operation, this is somewhat
an RT
> important. > > While in practise; given the previous patch; it will be very unlikely
Heh, that's not what semicolons are for ;-) Commas here, or a parenthetical.
> to ever really take more than one or two rounds, proving so becomes > rather hard. > > However, now that modifying wait_list is done while holding both > hb->lock and wait_lock, we can avoid the scenario entirely if we > acquire wait_lock while still holding hb-lock. Doing a hand-over, > without leaving a hole.
Nice :)
-- Darren Hart VMware Open Source Technology Center
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