Re: Configure template change to use SysV Semaphors on darwin

Using pgbench, on 1 million records at each of 1, 10 and 100
concurrent users, I get the same results before and after the patch.
I'm not sure if pgbench is the most appropriate benchmark for this
though.
The upside to using the SysV sema code on Darwin, to my
understanding, is that the SysV semaphores use less memory (and no
fd's). Darwin can support about 85k SysV semaphores system-wide, so
it has no need for tuning in that respect, which is nice.

Chris Marcellino

On Feb 7, 2007, at 4:54 PM, Tom Lane wrote:

> Chris Marcellino <cmarcellino(at)apple(dot)com> writes:
>> I searched through the archives and I can't find a mention of why the
>> posix_sema code was written for Darwin.
>
> Because Darwin didn't have anything else at the time.
>
>> If this is in fact the case, I have a trivial patch to conditionally
>> enable SysV semaphores based on the OS release:
>
> Outta curiosity, can you measure any performance difference?
>
> regards, tom lane
>
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