Unable to schedule a MMON slave?

From: <perivoj_at_net.hr>
Date: Tue, 12 Jun 2007 07:15:06 -0700
Message-ID: <1181657706.763271.131310@n15g2000prd.googlegroups.com>

I have growing mmon .trc in BDUMP:

...
*** 2007-06-12 15:59:18.617
Unable to schedule a MMON slave at: Auto Flush Main 1 Attempt to create slave process failed. Can happen for several reasons:

No process state objects
Reached OS set limits
A shutdown was going on Check alert log for more details. *** 2007-06-12 15:59:42.698 Unable to schedule a MMON slave at: Auto Purge Main 1 Attempt to create slave process failed. Can happen for several reasons:
No process state objects
Reached OS set limits
A shutdown was going on Check alert log for more details. *** 2007-06-12 16:00:18.810 Unable to schedule a MMON slave at: Auto Flush Main 1 Attempt to create slave process failed. Can happen for several reasons:
No process state objects
Reached OS set limits
A shutdown was going on Check alert log for more details. ...

and no details in alert log.

DB version: 10.1.0.4.0
OS: HP-UX B.11.11 U 9000/800
processes = 150 (max used 50) Received on Tue Jun 12 2007 - 09:15:06 CDT