dtrace discuss - Nov 2005 - system lib & user land & kernel lock

Hi:

On niagara system, I am trying to resolve the Lock contention
which results in low CPU usage.

I have probed the Mutex hold event for heavy expensive
lock releasing during user land processes test cycle.

Any way to further investigate the call below is contributed
by  system library, user land process or kernel lock.  This

Mutex Hold:

libsyssrv.so`__1cHSWMutexLmutexUnlock6M


Thanks
This message posted from opensolaris.org

ttoulliu2002 writes:
 > Hi:
 > 
 > On niagara system, I am trying to resolve the Lock contention
 > which results in low CPU usage.
 > 
 > I have probed the Mutex hold event for heavy expensive
 > lock releasing during user land processes test cycle.
 > 
 > Any way to further investigate the call below is contributed
 > by  system library, user land process or kernel lock.  This
 > 
 > Mutex Hold:
 > 
 > libsyssrv.so`__1cHSWMutexLmutexUnlock6M
 > 

I don''t know this lib. Is it third party ?
Try to grep for it in /var/sadm/install/contents.

Do you have the full ustack() associated with a long hold
time (at acquisition and release). 

Even then, it may not be sufficient. You need to track down
what is being executed in between. You mention low CPU usage 
so a lead could be to figure out if/where your thread is
going to sleep holding the lock.

sched:::sleep/self->lockheld/{@a[ustack(20),stack(20)]=count()}

-r



 > 
 > Thanks
 > This message posted from opensolaris.org
 > _______________________________________________
 > dtrace-discuss mailing list
 > dtrace-discuss at opensolaris.org