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Re: Dynamically allocated locks

Other than that its fine. I can see not crossing a cacheline boundary,
but only 1 / cacheline is just wrong.

It really does matter on MP systems. If you were to take a machine and have all CPUs doing nothing but modifying operations on data within a single cache line, then in the best case the machine would in effect be single threaded: it would do no better than a single CPU system. In the worst case it could be a lot slower due to (for example) costly writebacks to main

I understand that but in reality we are only talking about a handful of
lock per cacheline.  if the system has a few looks, this would be bad.
but as we go to finer grained locked, the chances of this being a problem drop dramatically. For high contention locks (like global lock), one per
cache line makes sense.  for low contention locks (like a socket lock),
multiple per cacheline makes sense.

maybe two pools, one for each type?

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