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 <[EMAIL PROTECTED]> 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

---------------------------(end of broadcast)---------------------------
TIP 7: You can help support the PostgreSQL project by donating at

                http://www.postgresql.org/about/donate


---------------------------(end of broadcast)---------------------------
TIP 7: You can help support the PostgreSQL project by donating at

               http://www.postgresql.org/about/donate

Reply via email to