Re: Spinlocks and CPU Architectures

>
> Do other people reach the same conclusions?
>
> Can we make a list of those architectures for which 8.1 is known to
> perform reasonably well, with reasonable SMP scalability? I suggest that
> we record this list somewhere in the release notes, but with a comment
> to say we run on other architectures, but they have not been SMP tested
> as of date of announcement. That is important, since the release notes
> make specific claim about scalability features.
>

I posted a message last week about some tests with Tom's recent spinlock
patches on a quad opteron server running Suse 9.2. I found that the patches
helped a great deal when the concurrency level was less than or equal to the
number of processors. When it was greater than that they didn't help nearly
as much and in fact at high concurrency levels the application would run
about as fast running on a single processor as on a quad. It was better than
without the patches but that's not what I could call good scalability on this
architecture.

Emil

P.S. I did put it into production last week since the gain when the
concurrency level was <= 4 was so pronounced and it appears to be working
well.