Re: Interrupt storm

[christos%astron.com@localhost (Christos Zoulas)]

In article <792173fe-8d3d-438a-ad47-713e6f54fe79%execsw.org@localhost>,
SAITOH Masanobu  <msaitoh%execsw.org@localhost> wrote:
>On 2018/10/24 23:09, Dima Veselov wrote:
>> Greetings,
>> 
>> I have two identical Dell R220 servers running NetBSD 8-STABLE
>> and they are working fine, but I noticed permanent high CPU
>> usage.
>> 
>> This always look like this:
>> 
>> 75 processes: 71 sleeping, 1 stopped, 3 on CPU
>> CPU0 states:  0.0% user,  0.0% nice,  0.7% system, 84.9% interrupt, 14.4% idle
>> CPU1 states:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  100% idle
>> CPU2 states:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  100% idle
>> CPU3 states:  0.0% user,  0.0% nice, 62.3% system,  0.0% interrupt, 37.7% idle
>> Memory: 3564M Act, 180K Inact, 7288K Wired, 83M Exec, 3020M File, 3272M Free
>> Swap: 2048M Total, 2048M Free
>> 
>>    PID USERNAME PRI NICE   SIZE   RES STATE      TIME   WCPU    CPU COMMAND
>>      0 root      96    0     0K   23M CPU/3     70.0H 79.15% 79.15% [system]
>> 
>> All other processes take 0% of anything.
>> System and interrupt percentage differ from time to time, but
>> it always take up to 100% of one core.
>> 
>> I think this is kind of a driver problem, but how can I identify
>> which hardware cause that load?

If you switch to the "threads" display by typing "t" you'll see the thread
that is using all the cpu. My guess is it is "ioflush".

christos