Messages in this thread | | | Date | Sun, 11 May 2008 09:29:43 -0600 | From | Matthew Wilcox <> | Subject | Re: [git pull] scheduler fixes |
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On Sun, May 11, 2008 at 05:19:09PM +0200, Ingo Molnar wrote: > * Matthew Wilcox <matthew@wil.cx> wrote: > > > exactly what usecase is that? Perhaps it could be converted to an > > > atomic counter + the wait_event() APIs. > > > > Effectively, it's a completion. It just works better with staggered > > wakeups than it does with the naive completion. > > So why not transform it to real completions instead? And if our current > 'struct completion' abstraction is insufficient for whatever reason, why > not extend that instead?
My point is that for the only user of counting semaphores and/or semaphores-abused-as-completions that has so far hit this race, the serialised wake-up performs better. You have not pointed at a scenario that _shows_ a parallel wake-up to perform better. Some hand-waving and talking about lofty principles, yes. But no actual data.
-- Intel are signing my paycheques ... these opinions are still mine "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step."
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