After I resume the system and plug something in one of the machine's USB3 ports (it doesn't happen if I plug the same device on a USB2 port), the CPU load raises to 50%, with one particular process with the highest load:
4 root 20 0 0 0 0 R 50.1 0.0 1:43.63 kworker/0:0
The problem seems to be caused by too many ACPI interrupts:
Description of problem:
After I resume the system and plug something in one of the machine's USB3 ports (it doesn't happen if I plug the same device on a USB2 port), the CPU load raises to 50%, with one particular process with the highest load:
4 root 20 0 0 0 0 R 50.1 0.0 1:43.63 kworker/0:0
The problem seems to be caused by too many ACPI interrupts:
root@ubuntu:~# grep -r . /sys/firmware/ acpi/interrupts / acpi/interrupts /sci:12554973 acpi/interrupts /error: 0 acpi/interrupts /gpe00: 0 invalid acpi/interrupts /gpe01: 0 invalid acpi/interrupts /gpe02: 0 enabled acpi/interrupts /gpe03: 0 disabled acpi/interrupts /gpe04: 0 disabled acpi/interrupts /gpe05: 0 disabled acpi/interrupts /gpe06: 0 enabled acpi/interrupts /gpe07: 0 invalid acpi/interrupts /gpe08: 0 invalid acpi/interrupts /gpe09: 0 disabled acpi/interrupts /gpe10: 0 invalid acpi/interrupts /gpe11: 0 invalid acpi/interrupts /gpe12: 0 invalid acpi/interrupts /gpe13: 0 invalid acpi/interrupts /gpe14: 0 invalid acpi/interrupts /gpe15: 0 invalid acpi/interrupts /gpe16: 0 invalid acpi/interrupts /gpe0A: 0 invalid acpi/interrupts /gpe17: 1504 enabled acpi/interrupts /gpe0B: 0 disabled acpi/interrupts /gpe18: 0 invalid acpi/interrupts /gpe0C: 0 disabled acpi/interrupts /gpe19: 0 invalid acpi/interrupts /gpe0D: 12553562 enabled acpi/interrupts /gpe0E: 0 disabled acpi/interrupts /gpe20: 0 disabled acpi/interrupts /gpe0F: 0 invalid acpi/interrupts /gpe21: 0 invalid acpi/interrupts /gpe22: 0 invalid acpi/interrupts /gpe23: 0 invalid acpi/interrupts /gpe24: 0 invalid acpi/interrupts /gpe25: 0 disabled acpi/interrupts /gpe26: 0 invalid acpi/interrupts /gpe1A: 0 invalid acpi/interrupts /gpe27: 0 invalid acpi/interrupts /gpe1B: 0 invalid acpi/interrupts /gpe28: 0 invalid acpi/interrupts /gpe1C: 0 invalid acpi/interrupts /gpe29: 0 invalid acpi/interrupts /gpe1D: 0 invalid acpi/interrupts /gpe1E: 0 enabled acpi/interrupts /gpe30: 0 invalid acpi/interrupts /gpe1F: 0 enabled acpi/interrupts /gpe31: 0 invalid acpi/interrupts /gpe32: 0 invalid acpi/interrupts /gpe33: 0 invalid acpi/interrupts /gpe34: 0 invalid acpi/interrupts /gpe35: 0 invalid acpi/interrupts /gpe36: 0 invalid acpi/interrupts /gpe2A: 0 invalid acpi/interrupts /gpe37: 0 invalid acpi/interrupts /gpe2B: 0 invalid acpi/interrupts /gpe38: 0 invalid acpi/interrupts /gpe2C: 0 invalid acpi/interrupts /gpe39: 0 invalid acpi/interrupts /gpe2D: 0 invalid acpi/interrupts /gpe2E: 0 invalid acpi/interrupts /gpe2F: 0 invalid acpi/interrupts /gpe3A: 0 invalid acpi/interrupts /gpe3B: 0 invalid acpi/interrupts /gpe3C: 0 invalid acpi/interrupts /gpe3D: 0 invalid acpi/interrupts /gpe3E: 0 invalid acpi/interrupts /gpe3F: 0 invalid acpi/interrupts /sci_not: 0 acpi/interrupts /ff_pmtimer: 0 invalid acpi/interrupts /ff_rt_ clk: 0 disabled acpi/interrupts /gpe_all: 12556159 acpi/interrupts /ff_gbl_ lock: 0 disabled acpi/interrupts /ff_pwr_ btn: 0 enabled acpi/interrupts /ff_slp_ btn: 0 invalid
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I can mitigate the problem by disabling that particular source
# echo disable > /sys/firmware/ acpi/interrupts /gpe0D
This also happens on Fedora 19 but doesn't happen on Ubuntu 13.04, so it seems the bug was introduced after the 3.8 kernel.
ProblemType: Bug 3.11.0- 5-generic 3.11.0-5.11 ature: Ubuntu 3.11.0-5.11-generic 3.11.0 controlC0: ubuntu 4220 F.... pulseaudio /casper/ initrd. lz file=/cdrom/ preseed/ hostname. seed boot=casper quiet splash -- persistent BOOT_IMAGE= /casper/ vmlinuz. efi ersions: restricted- modules- 3.11.0- 5-generic N/A backports- modules- 3.11.0- 5-generic N/A 045.130418. dg asset.tag: No Asset Tag NP1234567890 REVISION_ 1234567890ABCD asset.tag: No Asset Tag version: N/A MegatrendsInc. :bvrP08AAA. 045.130418. dg:bd04/ 18/2013: svnSAMSUNGELECT RONICSCO. ,LTD.:pn550P5C/ 550P7C: pvrP08AAA: rvnSAMSUNGELECT RONICSCO. ,LTD.:rnSAMSUNG _NP1234567890: rvrSEC_ SW_REVISION_ 1234567890ABCD: cvnSAMSUNGELECT RONICSCO. ,LTD.:ct9: cvrN/A: version: P08AAA
DistroRelease: Ubuntu 13.10
Package: linux-image-
ProcVersionSign
Uname: Linux 3.11.0-5-generic x86_64
ApportVersion: 2.12.1-0ubuntu3
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/
CasperVersion: 1.336
Date: Wed Sep 11 12:31:17 2013
LiveMediaBuild: Ubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130910)
MachineType: SAMSUNG ELECTRONICS CO., LTD. 550P5C/550P7C
MarkForUpload: True
ProcEnviron:
LANGUAGE=en_US
TERM=xterm
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: initrd=
PulseList:
Error: command ['pacmd', 'list'] failed with exit code 1: Home directory not accessible: Permission denied
No PulseAudio daemon running, or not running as session daemon.
RelatedPackageV
linux-
linux-
linux-firmware 1.113
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/18/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P08AAA.
dmi.board.
dmi.board.name: SAMSUNG_
dmi.board.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.board.version: SEC_SW_
dmi.chassis.
dmi.chassis.type: 9
dmi.chassis.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.chassis.
dmi.modalias: dmi:bvnAmerican
dmi.product.name: 550P5C/550P7C
dmi.product.
dmi.sys.vendor: SAMSUNG ELECTRONICS CO., LTD.