High interrupt CPU in top...

[Peter Harrison]

On 27 October 2014 21:31, Adam Vande More <amvandemore at gmail.com> wrote:

> On Mon, Oct 27, 2014 at 3:59 PM, Peter Harrison <
> four.harrisons at googlemail.com> wrote:
>
>> Can anyone help me diagnose this please? I'm on 10.0-RELEASE on a Thinkpad
>> X200s. In top I see around 30% CPU listed as 'interrupt' even when I'm
>> only
>> running Xorg (with Xfce as the window manager) with no other applications
>> open:
>>
>> last pid:  1946;  load averages:  1.09,  1.30,  1.24
>>                             up 0+00:59:59  21:56:20
>> 54 processes:  1 running, 53 sleeping
>> CPU:  0.4% user,  0.0% nice,  0.2% system, 32.8% interrupt, 66.6% idle
>> Mem: 188M Active, 282M Inact, 283M Wired, 22M Cache, 206M Buf, 1127M Free
>> Swap: 4096M Total, 4096M Free
>>
>>   PID USERNAME    THR PRI NICE   SIZE    RES STATE   C   TIME    WCPU
>> COMMAND
>>  1362 root          1  20    0   150M 25596K select  1   1:18   0.10% Xorg
>>  1613 peter         4  32    0   260M 21700K select  1   0:02   0.10%
>> xfce4-terminal
>>  1521 peter         1  20    0   159M 17652K select  1   0:10   0.00%
>> xfwm4
>>  1539 peter         1  20    0   152M 13704K select  1   0:08   0.00%
>> wrapper
>>  1524 peter         3  20    0   278M 24172K select  1   0:05   0.00%
>> xfce4-panel
>>  1444 haldaemon     2  28    0 60428K  6436K select  1   0:01   0.00% hald
>>  1511 peter         2  39    0   163M 14756K select  1   0:01   0.00%
>> xfce4-session
>>  1544 root          2  20    0 54908K  5904K select  1   0:01   0.00%
>> upowerd
>>  1526 peter         2  20    0   247M 16108K kqread  0   0:01   0.00%
>> xfdesktop
>>  1540 peter         1  20    0   156M 15480K select  1   0:01   0.00%
>> wrapper
>>  1279 messagebus    1  20    0 17044K  3144K select  0   0:00   0.00%
>> dbus-daemon
>>
>> How do I diagnose what's using my processor?
>>
>
> vmstat -i
>
> --
> Adam
>

Cheers Adam. That gives me:

[peter 181]> vmstat -i
interrupt                          total       rate
irq1: atkbd0                       11870          1
irq9: acpi0                        27499          4
irq12: psm0                       234774         39
irq16: uhci3                  1250818252     210292
irq20: hpet0 uhci0               6977995       1173
irq21: uhci1                          11          0
irq23: ehci0                           2          0
irq257: hdac0                      16380          2
irq258: iwn0                      559063         93
irq259: ahci0                     103732         17
irq260: vgapci0                   311808         52
Total                         1259061386     211678


Any idea why the uhci is causing such a high interrupt rate? Is that
normal? Sorry for being so noob.



Peter Harrison.