Re: Announce: Semaphore-Removal tree

[Matthew Wilcox <matthew@wil.cx>]

On Tue, Apr 29, 2008 at 10:09:30AM +1000, David Chinner wrote:
> > 2. l_flushsema
> > 
> > This seems to be a completion.  ie you're using it to wait for the log
> > to be flushed.
> 
> Yes, that could probably be a completion. I'm assuming that a completion
> can handle several thousand waiting processes, right?

By the way ... is it common that you get several thousand waiting
processes?  I ask because you wake them all up, then the herd thunders
into the l_icloglock spinlock.  Or is this a worst-case scenario that
happens once in a blue moon?

If l_flushsema does typically get more than one waiter, we can instead
wake the waiters one at a time.

-- 
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