Troubleshooting Guide

The message(s) occur(s) randomly and do(es) not appear to affect VINES performance. They occur if
VINES has missed processing an expired timed event (when the system processor is heavily loaded).
The event eventually gets processed, but not when it first expires.
VINES uses timers for processing and handling VINES Address Resolution Protocol (ARP) services,
Inter Processor Communication (IPC) sessions and retransmission, route aging, and some server
services.
These messages have been fixed in the Cisco IOS Software Release 12.0S and 12.1 main releases.
Multi Protocol Label Switching (MPLS)−related ProcessThese tracebacks can be generated on a
router configured for MPLS:
%SCHED−3−STUCKMTMR: Sleep w/expired mgd timer 60C0E9B4, time 0x3952
(00:00:00 ago).
−Process= "TDP Hello", ipl= 5, pid= 58
−Traceback= 600867F0 60086BB8 604390D4 60077E88 60077E74
%SCHED−3−STUCKMTMR: Sleep w/expired mgd timer 60CC2548, time 0x43006
(00:00:00 ago).
−Process= "Tag Control", ipl= 5, pid= 56
−Traceback= 600867F0 60086BB8 60448320 604484F0 60077E88 60077E74
Analysis of the event loops for the Tag Distribution Protocol (TDP), TDP Hello, and Tag control
processes shows that the loops could call a specific process_wait_for_event process without
processing all expired timers. The loops are fixed to ensure that all expired timers are processed
before suspending. This issue is solved in the latest Cisco IOS Software Release 12.0S and 12.1 main
releases.
•
This list of processes where this message can occur is non−exhaustive. It is always a cosmetic message and,
therefore, does not justify a Cisco IOS software upgrade. Be sure to run the latest Cisco IOS software release
in your train. If the message still appears in the latest Cisco IOS software release which is available on
Cisco.com for registered users, contact Cisco Technical Support to open a case. At this time, provide a
complete show log with the error messages and a show tech of the router or switch on which the problem
occurs.
SCHED−3−THRASHING
This message means that the indicated process has relinquished control 50 consecutive times and there are still
outstanding events to be processed.
These messages on the console indicate such a problem:
%SCHED−3−THRASHING: Process thrashing on watched queue
'ARP queue' (count 54).
−Process= "ARP Input", ipl= 5, pid= 6
−Traceback= 6020589C 60205BC4 60236520 601F4FD8 601F4FC4
These thrashing checks are intended to determine if a process is, for some reason, does not do its job. The
thrashing check on watched queues (which is the troublesome message which is signaling) checks the number
of elements on the queue. If this number remains the same for a given number of schedulings, the message is
printed.
Some queues are length−limited. This means that if the router gets very busy, the queues always stay at the
maximum. As a result, the thrashing code in the scheduler gets confused and thinks that these queues have not
been handled. The thrashing code has determined that the process which was supposed to handle the queue
was not doing its job and prints the thrashing message.