Re: Performance TODO items

> On Mon, 30 Jul 2001, Bruce Momjian wrote:
> 
> > * Improve spinlock code, perhaps with OS semaphores, sleeper queue, or
> >   spining to obtain lock on multi-cpu systems
> 
> You may be interested in a discussion which happened over on
> linux-kernel a few months ago.
> 
> Quite a lot of people want a lightweight userspace semaphore,
> and for pretty much the same reasons.
> 
> Linus proposed a pretty interesting solution which has the
> same minimal overhead as the current spinlocks in the non-
> contention case, but avoids the spin where there's contention:
> 
> http://www.mail-archive.com/linux-kernel%40vger.kernel.org/msg39615.html

Yes, many OS's have user-space spinlocks, for the same performance
reasons (no kernel call).

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