Tom wrote:
> > [ compare_and_swap man page ]
> 
> Looks kinda baroque.  What about the referenced fetch_and_or routine?
> If that's atomic it might be closer to TAS semantics.

Thanks for the hint!
Tatsuo, can you try the performance of fetch_and_or on your machine ?
Replace the cs() line in s_lock.h with the following:

<-- #define TAS(lock)       cs((int *) (lock), 0, 1)
--> #define TAS(lock)       fetch_and_or(lock, 1)

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

I don't know if that is enough difference to worry about.

Andreas

Tue, 15 Jan 2002 10:44:55 +0100
"Zeugswetter Andreas SB SD" <ZeugswetterA@spardat.at>
Re: 7.1 vs. 7.2 on AIX 5L 