Re: 7.1 vs. 7.2 on AIX 5L

 
> NOTICE:  LockRelease: no such lock
> 
> I'm afraid now the locking is broken. Will look into more.

Next try would be _check_lock (found in sys/atomic_op.h):

Description (from man page)

The _check_lock subroutine performs an atomic (uninterruptible) sequence of
operations. The compare_and_swap subroutine is similar, but does not issue
synchronization instructions and therefore is inappropriate for updating lock
words.

replace the TAS define with:
#define TAS(lock)       _check_lock(lock, 0, 1)

> with LinuxPPC asm:     2m9.340s
> with cs:            10m11.15s
> with fetch_and_or:    3m55.19s

with _check_lock:        3m29.990s

I think that the culprit may also be the S_UNLOCK (use _clear_lock) ?

Andreas