Symptom
BGP and/or BGP-IO-CONTROL processes are hogging the CPU on IOS XR devices after BGP table version wrap
Any of the below PAM messages are seen in 30 minutes intervals.
%OS-SYSLOG-4-LOG_WARNING : PAM detected bgp is hogging CPU on 0_RP0_CPU0!
%OS-SYSLOG-1-LOG_ALERT : PAM detected bgp-io-control is hogging CPU on 0_RSP1_CPU0!
%OS-SYSLOG-4-LOG_WARNING : PAM detected CPU hog for bgp on 0_RP0_CPU0.
Conditions
CPU hogging happens after BGP table version wrap.
Workaround
A workaround is possible if NSR is in effect.
Monitor with the command "show bgp all all process performance-statistics detail"
Wait until after the version wrap has completed.
Restart the standby RP.
Wait for NSR ready.
reload switchover.
The idea is that after the switchover, the new active RP has a low version and is not in a version wrapped state.
Further Problem Description
This redesign is integrated in the 7.5.2 release.
The code change in this bug cannot be back ported.
