>Synopsis: Kernel process drmwq spikes CPU usage every 20 seconds on
Protectcli Vault-2 Port hardware.
>Category: kernel
>Environment:
System : OpenBSD 7.2
Details : OpenBSD 7.2 (GENERIC.MP) #4: Mon Dec 12 06:06:42
MST 2022
r...@syspatch-72-amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP
Architecture: OpenBSD.amd64
Machine : amd64
>Description:
I use this machine as a router. After upgrading to 7.2 I
started getting pretty bad packet loss exactly every 20 seconds. After
some investigation I noticed the drmwq kernel process using a lot of CPU
every 20 seconds. When I plug a screen into the HDMI port on the
machine, it stops spiking the CPU and the problem goes away.
>How-To-Repeat:
Install OpenBSD 7.2 on a Protectcli Vault-2 port machine and
observe kernel threads, the CPU will spike exactly every 20 seconds.
This spike should cause packet loss that can be observed by running a ping.
>Fix:
Plug a screen into the HDMI port of the machine. The screen
does not have to be turned on.
dmesg:
OpenBSD 7.2 (GENERIC.MP) #4: Mon Dec 12 06:06:42 MST 2022
r...@syspatch-72-amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP
real mem = 8519704576 (8125MB)
avail mem = 8244084736 (7862MB)
random: good seed from bootblocks
mpath0 at root
scsibus0 at mpath0: 256 targets
mainbus0 at root
bios0 at mainbus0: SMBIOS rev. 2.7 @ 0x7cd1a020 (8 entries)
bios0: vendor coreboot version "v4.9.0.2" date 05/31/2021
bios0: Protectli FW2B
acpi0 at bios0: ACPI 3.0
acpi0: sleep states S0 S3 S4 S5
acpi0: tables DSDT FACP SSDT MCFG APIC
acpi0: wakeup devices XHCI(S3)
acpitimer0 at acpi0: 3579545 Hz, 24 bits
acpimcfg0 at acpi0
acpimcfg0: addr 0xe0000000, bus 0-255
acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Intel(R) Celeron(R) CPU J3060 @ 1.60GHz, 2480.24 MHz, 06-4c-04
cpu0:
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,SSE3,PCLMUL,DTES64,MWAIT,DS-CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,MOVBE,POPCNT,DEADLINE,AES,RDRAND,NXE,RDTSCP,LONG,LAHF,3DNOWP,PERF,ITSC,TSC_ADJUST,SMEP,ERMS,MD_CLEAR,IBRS,IBPB,STIBP,SENSOR,ARAT,MELTDOWN
cpu0: 24KB 64b/line 6-way D-cache, 32KB 64b/line 8-way I-cache, 1MB
64b/line 16-way L2 cache
cpu0: smt 0, core 0, package 0
mtrr: Pentium Pro MTRR support, 8 var ranges, 88 fixed ranges
cpu0: apic clock running at 79MHz
cpu0: mwait min=64, max=64, C-substates=0.2.0.0.0.0.3.3, IBE
cpu1 at mainbus0: apid 4 (application processor)
cpu1: Intel(R) Celeron(R) CPU J3060 @ 1.60GHz, 2479.97 MHz, 06-4c-04
cpu1:
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE,SSE3,PCLMUL,DTES64,MWAIT,DS-CPL,VMX,EST,TM2,SSSE3,CX16,xTPR,PDCM,SSE4.1,SSE4.2,MOVBE,POPCNT,DEADLINE,AES,RDRAND,NXE,RDTSCP,LONG,LAHF,3DNOWP,PERF,ITSC,TSC_ADJUST,SMEP,ERMS,MD_CLEAR,IBRS,IBPB,STIBP,SENSOR,ARAT,MELTDOWN
cpu1: 24KB 64b/line 6-way D-cache, 32KB 64b/line 8-way I-cache, 1MB
64b/line 16-way L2 cache
cpu1: smt 0, core 2, package 0
ioapic0 at mainbus0: apid 2 pa 0xfec00000, version 20, 115 pins
acpiprt0 at acpi0: bus 0 (PCI0)
acpipci0 at acpi0 PCI0: 0x00000000 0x00000011 0x00000001
"INT33BD" at acpi0 not configured
acpicmos0 at acpi0
com0 at acpi0 COM1 addr 0x3f8/0x8 irq 4: ns16550a, 16 byte fifo
"10EC5670" at acpi0 not configured
chvgpio0 at acpi0 GPSW uid 1 addr 0xfed80000/0x8000 irq 49, 56 pins
chvgpio1 at acpi0 GPNC uid 2 addr 0xfed88000/0x8000 irq 48, 59 pins
chvgpio2 at acpi0 GPEC uid 3 addr 0xfed90000/0x8000 irq 50, 24 pins
chvgpio3 at acpi0 GPSE uid 4 addr 0xfed98000/0x8000 irq 91, 55 pins
acpibtn0 at acpi0: PWRB
"BOOT0000" at acpi0 not configured
acpicpu0 at acpi0: C3(1@1500 mwait.1@0x52), C2(10@500 mwait.1@0x51),
C1(1000@1 mwait.1), PSS
acpicpu1 at acpi0: C3(1@1500 mwait.1@0x52), C2(10@500 mwait.1@0x51),
C1(1000@1 mwait.1), PSS
acpipwrres0 at acpi0: PLPE
cpu0: using VERW MDS workaround
cpu0: Enhanced SpeedStep 2480 MHz: speeds: 1601, 1600, 1520, 1440, 1360,
1280, 1200, 1120, 1040, 960, 880, 800, 720, 640, 560, 480 MHz
pci0 at mainbus0 bus 0
pchb0 at pci0 dev 0 function 0 "Intel Braswell Host" rev 0x35
inteldrm0 at pci0 dev 2 function 0 "Intel HD Graphics" rev 0x35
drm0 at inteldrm0
inteldrm0: msi, CHERRYVIEW, gen 8
"Intel Braswell Power" rev 0x35 at pci0 dev 11 function 0 not configured
ahci0 at pci0 dev 19 function 0 "Intel Braswell AHCI" rev 0x35: msi,
AHCI 1.3.1
ahci0: port 0: 6.0Gb/s
scsibus1 at ahci0: 32 targets
sd0 at scsibus1 targ 0 lun 0: <ATA, SanDisk SD8SFAT1, Z233>
naa.5001b444a6bd585c
sd0: 122104MB, 512 bytes/sector, 250069680 sectors, thin
xhci0 at pci0 dev 20 function 0 "Intel Braswell xHCI" rev 0x35: msi,
xHCI 1.0
usb0 at xhci0: USB revision 3.0
uhub0 at usb0 configuration 1 interface 0 "Intel xHCI root hub" rev
3.00/1.00 addr 1
"Intel Braswell SIO DMA" rev 0x35 at pci0 dev 24 function 0 not configured
"Intel Braswell SIO I2C" rev 0x35 at pci0 dev 24 function 1 not configured
"Intel Braswell SIO I2C" rev 0x35 at pci0 dev 24 function 2 not configured
azalia0 at pci0 dev 27 function 0 "Intel Braswell HD Audio" rev 0x35: msi
azalia0: codecs: Realtek ALC662, Intel/0x2883, using Realtek ALC662
audio0 at azalia0
ppb0 at pci0 dev 28 function 0 "Intel Braswell PCIE" rev 0x35: msi
pci1 at ppb0 bus 1
em0 at pci1 dev 0 function 0 "Intel I211" rev 0x03: msi, address
00:e0:67:26:67:10
ppb1 at pci0 dev 28 function 1 "Intel Braswell PCIE" rev 0x35: msi
pci2 at ppb1 bus 2
em1 at pci2 dev 0 function 0 "Intel I211" rev 0x03: msi, address
00:e0:67:26:67:11
"Intel Braswell SIO DMA" rev 0x35 at pci0 dev 30 function 0 not configured
pcib0 at pci0 dev 31 function 0 "Intel Braswell PCU LPC" rev 0x35
ichiic0 at pci0 dev 31 function 3 "Intel Braswell SMBus" rev 0x35: apic
2 int 18
iic0 at ichiic0
spdmem0 at iic0 addr 0x50: 8GB DDR3 SDRAM PC3-12800 SO-DIMM
isa0 at pcib0
isadma0 at isa0
pcppi0 at isa0 port 0x61
spkr0 at pcppi0
vmm0 at mainbus0: VMX/EPT (using slow L1TF mitigation)
uhub1 at uhub0 port 3 configuration 1 interface 0 "Terminus Technology
USB 2.0 Hub [MTT]" rev 2.00/1.00 addr 2
uhidev0 at uhub1 port 4 configuration 1 interface 0 "Cypress
Semiconductor Convertible 2 TKL" rev 2.00/0.00 addr 3
uhidev0: iclass 3/1
ukbd0 at uhidev0: 8 variable keys, 6 key codes, country code 33
wskbd0 at ukbd0: console keyboard
uhidev1 at uhub1 port 4 configuration 1 interface 1 "Cypress
Semiconductor Convertible 2 TKL" rev 2.00/0.00 addr 3
uhidev1: iclass 3/0, 2 report ids
ucc0 at uhidev1 reportid 1: 573 usages, 18 keys, array
wskbd1 at ucc0 mux 1
uhid0 at uhidev1 reportid 2: input=1, output=0, feature=0
vscsi0 at root
scsibus2 at vscsi0: 256 targets
softraid0 at root
scsibus3 at softraid0: 256 targets
root on sd0a (f16d9a5e891c2faa.a) swap on sd0b dump on sd0b
inteldrm0: 1920x1080, 32bpp
wsdisplay0 at inteldrm0 mux 1: console (std, vt100 emulation), using wskbd0
wskbd1: connecting to wsdisplay0
wsdisplay0: screen 1-5 added (std, vt100 emulation)
usbdevs:
Controller /dev/usb0:
addr 01: 8086:0000 Intel, xHCI root hub
super speed, self powered, config 1, rev 1.00
driver: uhub0
addr 02: 1a40:0101 Terminus Technology, USB 2.0 Hub [MTT]
high speed, self powered, config 1, rev 1.00
driver: uhub1
