HP-UX 11i v2 Read Before Installing or Updating, September 2006

Performance Degradation with Patch PHCO_33675
and PHCO_34718
If you installed patch PHCO_33675 or the newer
libpthread patch PHCO_34718 on your HP-UX 11i v2
system, applications on a loaded system holding shared
mutexes for a longer duration may see a performance
degradation. This problem is due to high spinning by
threads contending for shared mutex.
What to Do
Set the environment variable
PTHREAD_SHARED_MUTEX_OLDSPIN to "1 " to restore your
system performance.