Alan Stange wrote:
> Hello,
>
> I removed the whole tas_dummy() block for sparc from s_lock.c. I
> recompiled and installed with and without --enable-debug. I then ran
> pgbench on the box. This is using the Sun 11 compilers on Solaris 10.
>
> I tested using pgbench
>
> $ pgbench -i -s 32 pgbench
> $ pgbench -s 32 -c 1 -t 10000 -v
>
> for up to 8 clients on an 8 core UltraSparc IV+ system.
>
> Everything compiled and ran fine.
>
>
>
>
> I took a look at backend/port/tas/solaris_sparc.s file. Isn't that code
> a bit longer than needed?
>
> Aren't the callers of this doing
> while (tas(lock)) {
> // wait a bit without smashing the kernel/memory bus
> }
>
> in which case the code should just be
>
> ldstub [%o0],%o0
> retl
> nop
>
> without the extra comparisons and branching. Unless I'm missing something.
Basically the original 8.1 ASM code was placing its own address into the
shared memory address:
ldstub [%o0],%o0
and then based on what it got back, it was returning 1/0. The new code
in CVS HEAD places '1' in, so there is no longer a need for the tests.
--
Bruce Momjian http://candle.pha.pa.us
EnterpriseDB http://www.enterprisedb.com
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