| View previous topic :: View next topic |
| Author |
Message |
Fran
Guru
Joined: 29 Feb 2004
Posts: 530
Location: Coruña (Spain)
|
 Posted: Fri Mar 29, 2013 12:03 pm Post subject: [SOLVED] kworkers eating my cpu (again) |
 |
|
Sometimes I get a constant 30% use of my puny CPU (ULV SU4100) by one or two kworker threads. It isn't very annoying in the console, but on X it causes everything to stutter like crazy (including the mouse cursor). The computer gets unusable until it passses (sometimes in seconds, sometimes only after a reboot) or it simply freezes to a halt, forcing me to pull the battery.
In the past I already had this problem in this same laptop. I solved it by disabling drm kms polling. But recently (probably with 3.8, I'm not sure) it has appeared again, even with drm polling disabled.
(edit) I'm not alone:
https://bbs.archlinux.org/viewtopic.php?pid=1248190
http://verahill.blogspot.com.es/2013/03/368-slow-mouse-and-keyboard-triggered.html
Also with 3.8, also unrelated to drm kms polling. Does anyone know how to find out which kernel component causes the kworkers to get crazy? I could do a git bisect, but it's a big pain in the ass in a slow processor like the SU4100. I don't see anything weird in /sys/firmware/acpi/interrupts.
Last edited by Fran on Tue Apr 09, 2013 9:30 am; edited 1 time in total |
|
| Back to top |
|
 |
aCOSwt
Bodhisattva
Joined: 19 Oct 2007
Posts: 2537
Location: Hilbert space
|
| Posted: Fri Mar 29, 2013 12:28 pm Post subject: |
|
|
Can you spot on your system any particular interrupt "going mad" ? any particular thread displaying an unusual stime ?
_________________
|
|
| Back to top |
|
|
Fran
Guru
Joined: 29 Feb 2004
Posts: 530
Location: Coruña (Spain)
|
| Posted: Fri Mar 29, 2013 2:14 pm Post subject: |
|
|
| aCOSwt wrote: | | Can you spot on your system any particular interrupt "going mad" ? any particular thread displaying an unusual stime ? |
Nope and nope.
(edit) Wait, yeah. i915 starts interrupting like crazy:
| Code: | CPU0 CPU1
0: 35433 35563 IO-APIC-edge timer
1: 980 917 IO-APIC-edge i8042
8: 24 20 IO-APIC-edge rtc0
9: 68 72 IO-APIC-fasteoi acpi
12: 13887 13928 IO-APIC-edge i8042
16: 0 0 IO-APIC-fasteoi uhci_hcd:usb2, uhci_hcd:usb5
19: 0 0 IO-APIC-fasteoi ehci_hcd:usb1, uhci_hcd:usb4
23: 14 15 IO-APIC-fasteoi uhci_hcd:usb3, ehci_hcd:usb6
42: 113836 113519 PCI-MSI-edge i915
43: 15801 15858 PCI-MSI-edge ahci
44: 5804 5244 PCI-MSI-edge iwlwifi
45: 108 113 PCI-MSI-edge snd_hda_intel
NMI: 0 0 Non-maskable interrupts
LOC: 177735 180565 Local timer interrupts
SPU: 0 0 Spurious interrupts
PMI: 0 0 Performance monitoring interrupts
IWI: 0 0 IRQ work interrupts
RTR: 0 0 APIC ICR read retries
RES: 34498 22338 Rescheduling interrupts
CAL: 104 61 Function call interrupts
TLB: 1189 1143 TLB shootdowns
TRM: 12908 12908 Thermal event interrupts
THR: 0 0 Threshold APIC interrupts
MCE: 0 0 Machine check exceptions
MCP: 2 2 Machine check polls
ERR: 0
MIS: 0 |
Doesn't seem much higher than the rest, but that's because it had already stopped when I printed it. It was growing at a rate of 1000 interrupts/second instead of the usual 30 per second.
So, again it's caused by the damned i915 driver, like the last time it happened in 2.6 kernels. But this time it's not drm kms polling, unless there is a bug in 3.8 that ignores the setting in /sys/module/drm_kms_helper/parameters/poll |
|
| Back to top |
|
|
Fran
Guru
Joined: 29 Feb 2004
Posts: 530
Location: Coruña (Spain)
|
| Posted: Sat Mar 30, 2013 9:49 am Post subject: |
|
|
| Kernel 3.9_rc4 makes X usable again (even when i915 starts interrupting X doesn't stutter) but the i915 interrupt problem persists. |
|
| Back to top |
|
|
aCOSwt
Bodhisattva
Joined: 19 Oct 2007
Posts: 2537
Location: Hilbert space
|
| Posted: Sat Mar 30, 2013 10:35 am Post subject: |
|
|
| Fran wrote: | | Code: | CPU0 CPU1
TRM: 12908 12908 Thermal event interrupts |
|
should'nt kworkers Heating my cpu be the real title of your thread ? 
_________________
|
|
| Back to top |
|
|
Fran
Guru
Joined: 29 Feb 2004
Posts: 530
Location: Coruña (Spain)
|
| Posted: Sun Mar 31, 2013 9:32 am Post subject: |
|
|
| aCOSwt wrote: | | Fran wrote: | | Code: | CPU0 CPU1
TRM: 12908 12908 Thermal event interrupts |
|
should'nt kworkers Heating my cpu be the real title of your thread ? |
I actually have no idea what those events mean. Temperature doesn't go above 45º (coretemp).
Oh well. I suppose I'll be happy with 3.9-rc for now. I hate these random kernel bugs. I hope someone with a better CPU and larger hard disk is willing to bisect. |
|
| Back to top |
|
|
gamanakis
n00b
Joined: 04 Apr 2013
Posts: 1
|
|
| Back to top |
|
|
Fran
Guru
Joined: 29 Feb 2004
Posts: 530
Location: Coruña (Spain)
|
|
| Back to top |
|
|
|
Kernel & Hardware
