Re: LWLock contention: I think I understand the problem

> It would seem, therefore, that lwlock.c's behavior of immediately
> granting the lock to released waiters is not such a good idea after all.
> Perhaps we should release waiters but NOT grant them the lock; when they
> get to run, they have to loop back, try to get the lock, and possibly go
> back to sleep if they fail.  This apparent waste of cycles is actually
> beneficial because it saves context swaps overall.

I still need to think about this, but the above idea doesn't seem good. 
Right now, we wake only one waiting process who gets the lock while
other waiters stay sleeping, right?  If we don't give them the lock,
don't we have to wake up all the waiters?  If there are many, that
sounds like lots of context switches no?

I am still thinking.

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