Excessive amount of time in interrupt stack mode

[Carlos E Murillo-Sanchez]

emanuel stiebler via cctalk wrote:
> On 2019-04-29 13:11, Carlos E Murillo-Sanchez via cctalk wrote:
>> Dear ccmp'ers:
>>
>> For a while now, I noticed that my vaxstation 4000/60 with OpenVMS 7.2
>> had become sluggish, but I had not had the time to investigate the
>> problem.   The system is mostly idle, RAM is mostly free (there's 32mb),
>> there is almost no paging, but the CPU is spending upwards of 70% of the
>> time in the interrupt stack mode.  Currently, I am running it headless
>> because I have not had the time to fix the monitor (it still has the
>> framebuffer inside, but this sluggishness issue was present before with
>> the monitor attached).  I have read that this can be caused by "faulty
>> i/o devices that interrupt the cpu continuously".  What else can be done
>> to locate the source of the problem?
> SHOW DEV? doesn't show anything weird?
>
Interesting... I fired it up to run this command, and now it won't 
finish booting, it gets stuck at the
      %DECnet-I-LOADED, network base image loaded, version = 05.0D.00
message...  I do remember running the command and I did not notice any 
strange
error counts...

Will try a conversational boot later.  If not, I'll try to restore it 
from tape.

carlos.