Thomas Gleixner <tglx@xxxxxxxxxxxxx> writes:
Hi,
>> - nolapic=1 also helps
>
> Yeah, that's not surprising. Can you please provide /proc/interrupts for
> that with i915 module loaded ?
(All of this is on 4.16.17 !)
root@test:~# dmesg | grep apic
[ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz root=/dev/sda1 rootwait ro quiet nolapic=1
[ 0.000000] IOAPIC[0]: apic_id 8, version 32, address 0xfec00000, GSI 0-39
[ 0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz root=/dev/sda1 rootwait ro quiet nolapic=1
[ 0.014682] no APIC, boot with the "lapic" boot parameter to force-enable it.
[ 0.585601] intel_idle: lapic_timer_reliable_states 0xffffffff
root@test:~# cat /proc/interrupts
CPU0
0: 3267 XT-PIC timer
1: 5 XT-PIC i8042
2: 0 XT-PIC cascade
4: 1 XT-PIC ttyS0
5: 354 XT-PIC eth0
6: 343 XT-PIC snd_hda_intel:card0
8: 1 XT-PIC rtc0
9: 4 XT-PIC acpi
10: 4610 XT-PIC ahci[0000:00:1f.2], i801_smbus
11: 356 XT-PIC PCIe PME, pciehp, ehci_hcd:usb1, xhci-hcd:usb2, i915
12: 7 XT-PIC i8042
NMI: 0 Non-maskable interrupts
LOC: 0 Local timer interrupts
SPU: 0 Spurious interrupts
PMI: 0 Performance monitoring interrupts
IWI: 0 IRQ work interrupts
RTR: 0 APIC ICR read retries
RES: 0 Rescheduling interrupts
CAL: 0 Function call interrupts
TLB: 0 TLB shootdowns
TRM: 0 Thermal event interrupts
THR: 0 Threshold APIC interrupts
MCE: 0 Machine check exceptions
MCP: 1 Machine check polls
ERR: 8426
MIS: 0
PIN: 0 Posted-interrupt notification event
NPI: 0 Nested posted-interrupt event
PIW: 0 Posted-interrupt wakeup event
(With nolapic=1 there are many devices on int 11 ... with noapic=1 this
is much more distributed)
Some daemon is listening on /dev/ttyS0, so we have one interrupt from
opening. /dev/ttyS1 is unused. X11 was started via "startx", i.E. not
via some GDM. No DE was running, just OpenBox window manager and a Qt4
application that doesn't use OpenGL.
When I now run "stress-ng --fstat 0" it opens/closes all in /dev,
therefore also ttyS1. This increases the interrupts:
root@test:~# cat /proc/interrupts
CPU0
0: 5516 XT-PIC timer
1: 5 XT-PIC i8042
2: 0 XT-PIC cascade
3: 3472 XT-PIC
4: 1 XT-PIC ttyS0
5: 894 XT-PIC eth0
6: 343 XT-PIC snd_hda_intel:card0
8: 1 XT-PIC rtc0
9: 4 XT-PIC acpi
10: 4635 XT-PIC ahci[0000:00:1f.2], i801_smbus
11: 356 XT-PIC PCIe PME, pciehp, ehci_hcd:usb1, xhci-hcd:usb2, i915
12: 7 XT-PIC i8042
NMI: 0 Non-maskable interrupts
LOC: 0 Local timer interrupts
SPU: 0 Spurious interrupts
PMI: 0 Performance monitoring interrupts
IWI: 0 IRQ work interrupts
RTR: 0 APIC ICR read retries
RES: 0 Rescheduling interrupts
CAL: 0 Function call interrupts
TLB: 0 TLB shootdowns
TRM: 0 Thermal event interrupts
THR: 0 Threshold APIC interrupts
MCE: 0 Machine check exceptions
MCP: 1 Machine check polls
ERR: 14142
MIS: 0
PIN: 0 Posted-interrupt notification event
NPI: 0 Nested posted-interrupt event
PIW: 0 Posted-interrupt wakeup event
You could also see that int 11 counter did not increase.
> Could you please remove the i915 module and provide the output of
> lspci -vvv -s 00:02.0
***Without*** the module removed (i.E. x11 is running):
root@test:~# lspci -vvv -s 00:02.0
00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 0b) (prog-if 00 [VGA controller])
Subsystem: Intel Corporation Haswell-ULT Integrated Graphics Controller
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0
Interrupt: pin A routed to IRQ 11
Region 0: Memory at f7000000 (64-bit, non-prefetchable) [size=4M]
Region 2: Memory at e0000000 (64-bit, prefetchable) [size=256M]
Region 4: I/O ports at f000 [size=64]
[virtual] Expansion ROM at 000c0000 [disabled] [size=128K]
Capabilities: [90] MSI: Enable- Count=1/1 Maskable- 64bit-
Address: 00000000 Data: 0000
Capabilities: [d0] Power Management version 2
Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
Capabilities: [a4] PCI Advanced Features
AFCap: TP+ FLR+
AFCtrl: FLR-
AFStatus: TP-
Kernel driver in use: i915
Kernel modules: i915
And with i915 blacklisted and rebooted:
00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 0b) (prog-if 00 [VGA controller])
Subsystem: Intel Corporation Haswell-ULT Integrated Graphics Controller
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0
Interrupt: pin A routed to IRQ 11
Region 0: Memory at f7000000 (64-bit, non-prefetchable) [size=4M]
Region 2: Memory at e0000000 (64-bit, prefetchable) [size=256M]
Region 4: I/O ports at f000 [size=64]
[virtual] Expansion ROM at 000c0000 [disabled] [size=128K]
Capabilities: [90] MSI: Enable- Count=1/1 Maskable- 64bit-
Address: 00000000 Data: 0000
Capabilities: [d0] Power Management version 2
Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
Capabilities: [a4] PCI Advanced Features
AFCap: TP+ FLR+
AFCtrl: FLR-
AFStatus: TP-
Kernel modules: i915
