> > On my machine the various implemtations have the following runtimes:
> > (with a modified s_lock test that does not sleep, and
> > SPINS_PER_DELAY 100000)
> >
> > with LinuxPPC asm: 1m5.16s (Which may not work relyably on SMP)
> > with cs: 1m12.25s
> > with fetch_and_or: 1m26.71s
>
> Aah, there we have it. Same test on a slower 4Way SMP:
>
> with LinuxPPC asm: 2m9.340s
> with cs: 10m11.15s
> with fetch_and_or: 3m55.19s
>
> These numbers look more alarming.
> Unfortunately the man page for fetch_and_or does not mention anything
> about using it as a locking primitive. It is documented atomic though,
> so I guess that is enough.
>
> Andreas
>
I did several times of pgbenhc -c 10 -t 20 with the modification you
suggested and once got a hung (all backends sleeping with the status
showing "COMMIT"). Also I had an eror:
NOTICE: LockRelease: no such lock
I'm afraid now the locking is broken. Will look into more.
--
Tatsuo Ishii
