Yesterday I enabled witness(4) to debug something unrelated and started seeing traces during boot.
My kernel is up-to-date as of yesterday night. My inteldrm firmware is also up-to-date. The traces appear during every cold boot. Here is the most recent set from my last reboot, plucked from the dmesg: root on sd0a (847a92f1384e1964.a) swap on sd0b dump on sd0b witness: lock order reversal: 1st 0xfffffd844b4aad98 i915_active (&ref->mutex) 2nd 0xffff80000026ff10 vmlk (&vm->mutex) lock order "&vm->mutex"(rwlock) -> "&ref->mutex"(rwlock) first seen at: #0 witness_checkorder+0x466 #1 rw_enter+0x67 #2 i915_active_acquire+0x47 #3 i915_vma_pin+0x2c4 #4 i915_ggtt_pin+0x62 #5 intel_gt_init+0xb9 #6 i915_gem_init+0xa3 #7 i915_driver_probe+0x821 #8 inteldrm_attachhook+0x45 #9 config_process_deferred_mountroot+0x6b #10 main+0x723 lock order "&ref->mutex"(rwlock) -> "&vm->mutex"(rwlock) first seen at: #0 witness_checkorder+0x466 #1 rw_enter+0x67 #2 i915_vma_pin+0x250 #3 i915_ggtt_pin+0x62 #4 intel_ring_pin+0x65 #5 __intel_context_active+0x33 #6 i915_active_acquire+0x85 #7 __intel_context_do_pin+0x3b #8 intel_engines_init+0x4e1 #9 intel_gt_init+0x130 #10 i915_gem_init+0xa3 #11 i915_driver_probe+0x821 #12 inteldrm_attachhook+0x45 #13 config_process_deferred_mountroot+0x6b #14 main+0x723 witness: acquiring duplicate lock of same type: "&ref->mutex" 1st i915_active 2nd i915_active Starting stack trace... witness_checkorder(ffff800000eb23c8,9,0) at witness_checkorder+0x809 rw_enter(ffff800000eb23b8,11) at rw_enter+0x67 i915_active_acquire(ffff800000eb23b0) at i915_active_acquire+0x47 __intel_context_active(fffffd844b4aad80) at __intel_context_active+0x4d i915_active_acquire(fffffd844b4aad80) at i915_active_acquire+0x85 __intel_context_do_pin(fffffd844b4aacb0) at __intel_context_do_pin+0x3b intel_engines_init(ffff800000272060) at intel_engines_init+0x4e1 intel_gt_init(ffff800000272060) at intel_gt_init+0x130 i915_gem_init(ffff80000026d000) at i915_gem_init+0xa3 i915_driver_probe(ffff80000026d000,ffffffff82029be8) at i915_driver_probe+0x821 inteldrm_attachhook(ffff80000026d000) at inteldrm_attachhook+0x45 config_process_deferred_mountroot() at config_process_deferred_mountroot+0x6b main(0) at main+0x723 end trace frame: 0x0, count: 244 End of stack trace. inteldrm0: 2560x1440, 32bpp wsdisplay0 at inteldrm0 mux 1: console (std, vt100 emulation), using wskbd0 wsdisplay0: screen 1-5 added (std, vt100 emulation) iwm0: hw rev 0x230, fw ver 34.0.1, address 98:3b:8f:ef:6b:ef witness: acquiring duplicate lock of same type: "&wf->mutex" 1st wakeref.mutex 2nd wakeref.mutex Starting stack trace... witness_checkorder(ffff800000272500,9,0) at witness_checkorder+0x809 rw_enter_write(ffff8000002724f0) at rw_enter_write+0x43 __intel_wakeref_get_first(ffff8000002724e8) at __intel_wakeref_get_first+0x28 __engine_unpark(ffff80000086c180) at __engine_unpark+0x46 __intel_wakeref_get_first(ffff80000086c180) at __intel_wakeref_get_first+0x4a i915_active_acquire_preallocate_barrier(fffffd83d3bf5d88,ffff80000086c000) at i915_active_acquire_preallocate_barrier+0xa8 __intel_context_do_pin(fffffd83d3bf5cb8) at __intel_context_do_pin+0xa6 i915_gem_do_execbuffer(ffff80000026d078,ffff800001364000,ffff8000451ff000,ffff80000135a800,0) at i915_gem_do_execbuffer+0x288f i915_gem_execbuffer2_ioctl(ffff80000026d078,ffff8000451ff000,ffff800001364000) at i915_gem_execbuffer2_ioctl+0x1da drm_do_ioctl(ffff80000026d078,100,80406469,ffff8000451ff000) at drm_do_ioctl+0x274 drmioctl(15700,80406469,ffff8000451ff000,3,ffff8000452c2f98) at drmioctl+0xdc VOP_IOCTL(fffffd83d1e435c8,80406469,ffff8000451ff000,3,fffffd8450fa8480,ffff8000452c2f98) at VOP_IOCTL+0x55 vn_ioctl(fffffd83d22725f8,80406469,ffff8000451ff000,ffff8000452c2f98) at vn_ioctl+0x75 sys_ioctl(ffff8000452c2f98,ffff8000451ff110,ffff8000451ff170) at sys_ioctl+0x2d4 syscall(ffff8000451ff1e0) at syscall+0x389 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffca3a0, count: 241 End of stack trace. witness: acquiring duplicate lock of same type: "&rq->lock" 1st &rq->lock 2nd &rq->lock Starting stack trace... witness_checkorder(ffff80000147a628,9,0) at witness_checkorder+0x809 mtx_enter(ffff80000147a618) at mtx_enter+0x3c i915_active_ref(ffff8000014a2bf0,ffff800001477000,ffff80000147a2e8) at i915_active_ref+0x1fd i915_vma_move_to_active(ffff8000014a2af8,ffff80000147a2e8,80000018) at i915_vma_move_to_active+0x5c i915_gem_do_execbuffer(ffff80000026d078,ffff800001364000,ffff8000451ff000,ffff800001483000,0) at i915_gem_do_execbuffer+0x323a i915_gem_execbuffer2_ioctl(ffff80000026d078,ffff8000451ff000,ffff800001364000) at i915_gem_execbuffer2_ioctl+0x1da drm_do_ioctl(ffff80000026d078,100,80406469,ffff8000451ff000) at drm_do_ioctl+0x274 drmioctl(15700,80406469,ffff8000451ff000,3,ffff8000452c2f98) at drmioctl+0xdc VOP_IOCTL(fffffd83d1e435c8,80406469,ffff8000451ff000,3,fffffd8450fa8480,ffff8000452c2f98) at VOP_IOCTL+0x55 vn_ioctl(fffffd83d22725f8,80406469,ffff8000451ff000,ffff8000452c2f98) at vn_ioctl+0x75 sys_ioctl(ffff8000452c2f98,ffff8000451ff110,ffff8000451ff170) at sys_ioctl+0x2d4 syscall(ffff8000451ff1e0) at syscall+0x389 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffca190, count: 244 End of stack trace. Here's my full dmesg, traces and all: OpenBSD 6.8-beta (GENERIC.MP) #145: Wed Sep 16 13:36:34 CDT 2020 ssc@jetsam.local:/usr/src/sys/arch/amd64/compile/GENERIC.MP real mem = 16895528960 (16112MB) avail mem = 16238313472 (15486MB) random: good seed from bootblocks mpath0 at root scsibus0 at mpath0: 256 targets mainbus0 at root bios0 at mainbus0: SMBIOS rev. 3.0 @ 0x9f03b000 (63 entries) bios0: vendor LENOVO version "N23ET59W (1.34 )" date 11/08/2018 bios0: LENOVO 20KHCTO1WW acpi0 at bios0: ACPI 5.0 acpi0: sleep states S0 S3 S4 S5 acpi0: tables DSDT FACP SSDT SSDT TPM2 UEFI SSDT SSDT HPET APIC MCFG ECDT SSDT SSDT BOOT BATB SSDT SSDT SSDT LPIT WSMT SSDT SSDT SSDT DBGP DBG2 MSDM DMAR NHLT ASF! FPDT UEFI acpi0: wakeup devices GLAN(S4) XHC_(S3) XDCI(S4) HDAS(S4) RP01(S4) PXSX(S4) RP02(S4) PXSX(S4) PXSX(S4) RP04(S4) PXSX(S4) RP05(S4) PXSX(S4) RP06(S4) PXSX(S4) RP07(S4) [...] acpitimer0 at acpi0: 3579545 Hz, 24 bits acpihpet0 at acpi0: 23999999 Hz acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat cpu0 at mainbus0: apid 0 (boot processor) cpu0: Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz, 1796.65 MHz, 06-8e-0a 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,SMX,EST,TM2,SSSE3,SDBG,FMA3,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,MOVBE,POPCNT,DEADLINE,AES,XSAVE,AVX,F16C,RDRAND,NXE,PAGE1GB,RDTSCP,LONG,LAHF,ABM,3DNOWP,PERF,ITSC,FSGSBASE,TSC_ADJUST,SGX,BMI1,HLE,AVX2,SMEP,BMI2,ERMS,INVPCID,RTM,MPX,RDSEED,ADX,SMAP,CLFLUSHOPT,PT,SRBDS_CTRL,MD_CLEAR,TSXFA,IBRS,IBPB,STIBP,L1DF,SSBD,SENSOR,ARAT,XSAVEOPT,XSAVEC,XGETBV1,XSAVES,MELTDOWN cpu0: 256KB 64b/line 8-way L2 cache cpu0: smt 0, core 0, package 0 mtrr: Pentium Pro MTRR support, 10 var ranges, 88 fixed ranges cpu0: apic clock running at 24MHz cpu0: mwait min=64, max=64, C-substates=0.2.1.2.4.1.1.1, IBE cpu1 at mainbus0: apid 2 (application processor) cpu1: Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz, 1795.82 MHz, 06-8e-0a 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,SMX,EST,TM2,SSSE3,SDBG,FMA3,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,MOVBE,POPCNT,DEADLINE,AES,XSAVE,AVX,F16C,RDRAND,NXE,PAGE1GB,RDTSCP,LONG,LAHF,ABM,3DNOWP,PERF,ITSC,FSGSBASE,TSC_ADJUST,SGX,BMI1,HLE,AVX2,SMEP,BMI2,ERMS,INVPCID,RTM,MPX,RDSEED,ADX,SMAP,CLFLUSHOPT,PT,SRBDS_CTRL,MD_CLEAR,TSXFA,IBRS,IBPB,STIBP,L1DF,SSBD,SENSOR,ARAT,XSAVEOPT,XSAVEC,XGETBV1,XSAVES,MELTDOWN cpu1: 256KB 64b/line 8-way L2 cache cpu1: smt 0, core 1, package 0 cpu2 at mainbus0: apid 4 (application processor) cpu2: Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz, 1795.84 MHz, 06-8e-0a cpu2: 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,SMX,EST,TM2,SSSE3,SDBG,FMA3,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,MOVBE,POPCNT,DEADLINE,AES,XSAVE,AVX,F16C,RDRAND,NXE,PAGE1GB,RDTSCP,LONG,LAHF,ABM,3DNOWP,PERF,ITSC,FSGSBASE,TSC_ADJUST,SGX,BMI1,HLE,AVX2,SMEP,BMI2,ERMS,INVPCID,RTM,MPX,RDSEED,ADX,SMAP,CLFLUSHOPT,PT,SRBDS_CTRL,MD_CLEAR,TSXFA,IBRS,IBPB,STIBP,L1DF,SSBD,SENSOR,ARAT,XSAVEOPT,XSAVEC,XGETBV1,XSAVES,MELTDOWN cpu2: 256KB 64b/line 8-way L2 cache cpu2: smt 0, core 2, package 0 cpu3 at mainbus0: apid 6 (application processor) cpu3: Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz, 1795.82 MHz, 06-8e-0a cpu3: 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,SMX,EST,TM2,SSSE3,SDBG,FMA3,CX16,xTPR,PDCM,PCID,SSE4.1,SSE4.2,x2APIC,MOVBE,POPCNT,DEADLINE,AES,XSAVE,AVX,F16C,RDRAND,NXE,PAGE1GB,RDTSCP,LONG,LAHF,ABM,3DNOWP,PERF,ITSC,FSGSBASE,TSC_ADJUST,SGX,BMI1,HLE,AVX2,SMEP,BMI2,ERMS,INVPCID,RTM,MPX,RDSEED,ADX,SMAP,CLFLUSHOPT,PT,SRBDS_CTRL,MD_CLEAR,TSXFA,IBRS,IBPB,STIBP,L1DF,SSBD,SENSOR,ARAT,XSAVEOPT,XSAVEC,XGETBV1,XSAVES,MELTDOWN cpu3: 256KB 64b/line 8-way L2 cache cpu3: smt 0, core 3, package 0 ioapic0 at mainbus0: apid 2 pa 0xfec00000, version 20, 120 pins acpimcfg0 at acpi0 acpimcfg0: addr 0xf0000000, bus 0-127 acpiec0 at acpi0 acpiprt0 at acpi0: bus 0 (PCI0) acpiprt1 at acpi0: bus 2 (RP01) acpiprt2 at acpi0: bus -1 (RP02) acpiprt3 at acpi0: bus -1 (RP03) acpiprt4 at acpi0: bus -1 (RP04) acpiprt5 at acpi0: bus 4 (RP05) acpiprt6 at acpi0: bus -1 (RP06) acpiprt7 at acpi0: bus -1 (RP07) acpiprt8 at acpi0: bus -1 (RP08) acpiprt9 at acpi0: bus -1 (RP09) acpiprt10 at acpi0: bus -1 (RP10) acpiprt11 at acpi0: bus -1 (RP11) acpiprt12 at acpi0: bus -1 (RP12) acpiprt13 at acpi0: bus -1 (RP13) acpiprt14 at acpi0: bus -1 (RP14) acpiprt15 at acpi0: bus -1 (RP15) acpiprt16 at acpi0: bus -1 (RP16) acpiprt17 at acpi0: bus -1 (RP17) acpiprt18 at acpi0: bus -1 (RP18) acpiprt19 at acpi0: bus -1 (RP19) acpiprt20 at acpi0: bus -1 (RP20) acpiprt21 at acpi0: bus -1 (RP21) acpiprt22 at acpi0: bus -1 (RP22) acpiprt23 at acpi0: bus -1 (RP23) acpiprt24 at acpi0: bus -1 (RP24) acpipci0 at acpi0 PCI0: 0x00000000 0x00000011 0x00000001 extent `acpipci0 pcibus' (0x0 - 0xff), flags=0 0x7f - 0xff extent `acpipci0 pciio' (0x0 - 0xffffffff), flags=0 0xcf8 - 0xcff 0x10000 - 0xffffffff extent `acpipci0 pcimem' (0x0 - 0xffffffffffffffff), flags=0 0x0 - 0x9ffff 0xc0000 - 0xac7fffff 0xf0000000 - 0xfcffffff 0xfe800000 - 0x1fffffffff 0x3000000000 - 0xffffffffffffffff acpithinkpad0 at acpi0: version 2.0 acpiac0 at acpi0: AC unit online acpibat0 at acpi0: BAT0 model "01AV430" serial 3080 type LiP oem "SMP" "LEN0100" at acpi0 not configured "INT3403" at acpi0 not configured acpicmos0 at acpi0 "ALPS0000" at acpi0 not configured "INT0E0C" at acpi0 not configured acpibtn0 at acpi0: SLPB "PNP0C14" at acpi0 not configured acpibtn1 at acpi0: LID_ "PNP0C14" at acpi0 not configured "PNP0C14" at acpi0 not configured "PNP0C14" at acpi0 not configured "PNP0C14" at acpi0 not configured "INT3400" at acpi0 not configured "STM7304" at acpi0 not configured acpicpu0 at acpi0: C3(200@1034 mwait.1@0x60), C2(200@151 mwait.1@0x33), C1(1000@1 mwait.1), PSS acpicpu1 at acpi0: C3(200@1034 mwait.1@0x60), C2(200@151 mwait.1@0x33), C1(1000@1 mwait.1), PSS acpicpu2 at acpi0: C3(200@1034 mwait.1@0x60), C2(200@151 mwait.1@0x33), C1(1000@1 mwait.1), PSS acpicpu3 at acpi0: C3(200@1034 mwait.1@0x60), C2(200@151 mwait.1@0x33), C1(1000@1 mwait.1), PSS acpipwrres0 at acpi0: PUBS, resource for XHC_ acpitz0 at acpi0: critical temperature is 128 degC acpivideo0 at acpi0: GFX0 acpivout0 at acpivideo0: DD1F cpu0: using VERW MDS workaround (except on vmm entry) cpu0: Enhanced SpeedStep 1796 MHz: speeds: 2101, 2100, 1900, 1800, 1700, 1600, 1500, 1400, 1200, 1100, 1000, 800, 700, 600, 500, 400 MHz pci0 at mainbus0 bus 0 pchb0 at pci0 dev 0 function 0 "Intel Core 8G Host" rev 0x08 inteldrm0 at pci0 dev 2 function 0 "Intel UHD Graphics 620" rev 0x07 drm0 at inteldrm0 inteldrm0: msi, KABYLAKE, gen 9 "Intel Core 6G Thermal" rev 0x08 at pci0 dev 4 function 0 not configured "Intel Core GMM" rev 0x00 at pci0 dev 8 function 0 not configured xhci0 at pci0 dev 20 function 0 "Intel 100 Series xHCI" rev 0x21: 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 pchtemp0 at pci0 dev 20 function 2 "Intel 100 Series Thermal" rev 0x21 "Intel 100 Series MEI" rev 0x21 at pci0 dev 22 function 0 not configured ppb0 at pci0 dev 28 function 0 "Intel 100 Series PCIE" rev 0xf1: msi pci1 at ppb0 bus 2 iwm0 at pci1 dev 0 function 0 "Intel Dual Band Wireless-AC 8265" rev 0x78, msi ppb1 at pci0 dev 28 function 4 "Intel 100 Series PCIE" rev 0xf1: msi pci2 at ppb1 bus 4 nvme0 at pci2 dev 0 function 0 "Samsung SM981/PM981 NVMe" rev 0x00: msix, NVMe 1.2 nvme0: SAMSUNG MZVLB1T0HALR-000L7, firmware 4L2QEXA7, serial S3TPNX0K919907 scsibus1 at nvme0: 2 targets, initiator 0 sd0 at scsibus1 targ 1 lun 0: <NVMe, SAMSUNG MZVLB1T0, 4L2Q> sd0: 976762MB, 512 bytes/sector, 2000409264 sectors pcib0 at pci0 dev 31 function 0 "Intel 200 Series LPC" rev 0x21 "Intel 100 Series PMC" rev 0x21 at pci0 dev 31 function 2 not configured azalia0 at pci0 dev 31 function 3 "Intel 200 Series HD Audio" rev 0x21: msi azalia0: codecs: Realtek ALC285, Intel/0x280b, using Realtek ALC285 audio0 at azalia0 ichiic0 at pci0 dev 31 function 4 "Intel 100 Series SMBus" rev 0x21: apic 2 int 16 iic0 at ichiic0 em0 at pci0 dev 31 function 6 "Intel I219-LM" rev 0x21: msi, address e8:6a:64:78:68:5f isa0 at pcib0 isadma0 at isa0 pckbc0 at isa0 port 0x60/5 irq 1 irq 12 pckbd0 at pckbc0 (kbd slot) wskbd0 at pckbd0: console keyboard pms0 at pckbc0 (aux slot) wsmouse0 at pms0 mux 0 wsmouse1 at pms0 mux 0 pms0: Synaptics clickpad, firmware 9.16, 0x1e2a1 0x940300 0x33d840 0xf00ba3 0x12e800 pcppi0 at isa0 port 0x61 spkr0 at pcppi0 vmm0 at mainbus0: VMX/EPT efifb at mainbus0 not configured uvideo0 at uhub0 port 5 configuration 1 interface 0 "SunplusIT Inc Integrated IR Camera" rev 2.01/0.12 addr 2 video0 at uvideo0 ugen0 at uhub0 port 7 "Intel Bluetooth" rev 2.00/0.10 addr 3 uvideo1 at uhub0 port 8 configuration 1 interface 0 "Chicony Electronics Co.,Ltd. Integrated Camera" rev 2.01/0.12 addr 4 video1 at uvideo1 ugen1 at uhub0 port 9 "Synaptics product 0x009a" rev 2.00/1.64 addr 5 umass0 at uhub0 port 15 configuration 1 interface 0 "Generic USB3.0-CRW" rev 3.00/29.08 addr 6 umass0: using SCSI over Bulk-Only scsibus2 at umass0: 2 targets, initiator 0 sd1 at scsibus2 targ 1 lun 0: <Generic-, SD/MMC CRW, 1.00> removable serial.0bda0328008282014000 vscsi0 at root scsibus3 at vscsi0: 256 targets softraid0 at root scsibus4 at softraid0: 256 targets root on sd0a (847a92f1384e1964.a) swap on sd0b dump on sd0b witness: lock order reversal: 1st 0xfffffd844b4aad98 i915_active (&ref->mutex) 2nd 0xffff80000026ff10 vmlk (&vm->mutex) lock order "&vm->mutex"(rwlock) -> "&ref->mutex"(rwlock) first seen at: #0 witness_checkorder+0x466 #1 rw_enter+0x67 #2 i915_active_acquire+0x47 #3 i915_vma_pin+0x2c4 #4 i915_ggtt_pin+0x62 #5 intel_gt_init+0xb9 #6 i915_gem_init+0xa3 #7 i915_driver_probe+0x821 #8 inteldrm_attachhook+0x45 #9 config_process_deferred_mountroot+0x6b #10 main+0x723 lock order "&ref->mutex"(rwlock) -> "&vm->mutex"(rwlock) first seen at: #0 witness_checkorder+0x466 #1 rw_enter+0x67 #2 i915_vma_pin+0x250 #3 i915_ggtt_pin+0x62 #4 intel_ring_pin+0x65 #5 __intel_context_active+0x33 #6 i915_active_acquire+0x85 #7 __intel_context_do_pin+0x3b #8 intel_engines_init+0x4e1 #9 intel_gt_init+0x130 #10 i915_gem_init+0xa3 #11 i915_driver_probe+0x821 #12 inteldrm_attachhook+0x45 #13 config_process_deferred_mountroot+0x6b #14 main+0x723 witness: acquiring duplicate lock of same type: "&ref->mutex" 1st i915_active 2nd i915_active Starting stack trace... witness_checkorder(ffff800000eb23c8,9,0) at witness_checkorder+0x809 rw_enter(ffff800000eb23b8,11) at rw_enter+0x67 i915_active_acquire(ffff800000eb23b0) at i915_active_acquire+0x47 __intel_context_active(fffffd844b4aad80) at __intel_context_active+0x4d i915_active_acquire(fffffd844b4aad80) at i915_active_acquire+0x85 __intel_context_do_pin(fffffd844b4aacb0) at __intel_context_do_pin+0x3b intel_engines_init(ffff800000272060) at intel_engines_init+0x4e1 intel_gt_init(ffff800000272060) at intel_gt_init+0x130 i915_gem_init(ffff80000026d000) at i915_gem_init+0xa3 i915_driver_probe(ffff80000026d000,ffffffff82029be8) at i915_driver_probe+0x821 inteldrm_attachhook(ffff80000026d000) at inteldrm_attachhook+0x45 config_process_deferred_mountroot() at config_process_deferred_mountroot+0x6b main(0) at main+0x723 end trace frame: 0x0, count: 244 End of stack trace. inteldrm0: 2560x1440, 32bpp wsdisplay0 at inteldrm0 mux 1: console (std, vt100 emulation), using wskbd0 wsdisplay0: screen 1-5 added (std, vt100 emulation) iwm0: hw rev 0x230, fw ver 34.0.1, address 98:3b:8f:ef:6b:ef witness: acquiring duplicate lock of same type: "&wf->mutex" 1st wakeref.mutex 2nd wakeref.mutex Starting stack trace... witness_checkorder(ffff800000272500,9,0) at witness_checkorder+0x809 rw_enter_write(ffff8000002724f0) at rw_enter_write+0x43 __intel_wakeref_get_first(ffff8000002724e8) at __intel_wakeref_get_first+0x28 __engine_unpark(ffff80000086c180) at __engine_unpark+0x46 __intel_wakeref_get_first(ffff80000086c180) at __intel_wakeref_get_first+0x4a i915_active_acquire_preallocate_barrier(fffffd83d3bf5d88,ffff80000086c000) at i915_active_acquire_preallocate_barrier+0xa8 __intel_context_do_pin(fffffd83d3bf5cb8) at __intel_context_do_pin+0xa6 i915_gem_do_execbuffer(ffff80000026d078,ffff800001364000,ffff8000451ff000,ffff80000135a800,0) at i915_gem_do_execbuffer+0x288f i915_gem_execbuffer2_ioctl(ffff80000026d078,ffff8000451ff000,ffff800001364000) at i915_gem_execbuffer2_ioctl+0x1da drm_do_ioctl(ffff80000026d078,100,80406469,ffff8000451ff000) at drm_do_ioctl+0x274 drmioctl(15700,80406469,ffff8000451ff000,3,ffff8000452c2f98) at drmioctl+0xdc VOP_IOCTL(fffffd83d1e435c8,80406469,ffff8000451ff000,3,fffffd8450fa8480,ffff8000452c2f98) at VOP_IOCTL+0x55 vn_ioctl(fffffd83d22725f8,80406469,ffff8000451ff000,ffff8000452c2f98) at vn_ioctl+0x75 sys_ioctl(ffff8000452c2f98,ffff8000451ff110,ffff8000451ff170) at sys_ioctl+0x2d4 syscall(ffff8000451ff1e0) at syscall+0x389 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffca3a0, count: 241 End of stack trace. witness: acquiring duplicate lock of same type: "&rq->lock" 1st &rq->lock 2nd &rq->lock Starting stack trace... witness_checkorder(ffff80000147a628,9,0) at witness_checkorder+0x809 mtx_enter(ffff80000147a618) at mtx_enter+0x3c i915_active_ref(ffff8000014a2bf0,ffff800001477000,ffff80000147a2e8) at i915_active_ref+0x1fd i915_vma_move_to_active(ffff8000014a2af8,ffff80000147a2e8,80000018) at i915_vma_move_to_active+0x5c i915_gem_do_execbuffer(ffff80000026d078,ffff800001364000,ffff8000451ff000,ffff800001483000,0) at i915_gem_do_execbuffer+0x323a i915_gem_execbuffer2_ioctl(ffff80000026d078,ffff8000451ff000,ffff800001364000) at i915_gem_execbuffer2_ioctl+0x1da drm_do_ioctl(ffff80000026d078,100,80406469,ffff8000451ff000) at drm_do_ioctl+0x274 drmioctl(15700,80406469,ffff8000451ff000,3,ffff8000452c2f98) at drmioctl+0xdc VOP_IOCTL(fffffd83d1e435c8,80406469,ffff8000451ff000,3,fffffd8450fa8480,ffff8000452c2f98) at VOP_IOCTL+0x55 vn_ioctl(fffffd83d22725f8,80406469,ffff8000451ff000,ffff8000452c2f98) at vn_ioctl+0x75 sys_ioctl(ffff8000452c2f98,ffff8000451ff110,ffff8000451ff170) at sys_ioctl+0x2d4 syscall(ffff8000451ff1e0) at syscall+0x389 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffca190, count: 244 End of stack trace. And here's pcidump -v: Domain /dev/pci0: 0:0:0: Intel Core 8G Host 0x0000: Vendor ID: 8086, Product ID: 5914 0x0004: Command: 0006, Status: 2090 0x0008: Class: 06 Bridge, Subclass: 00 Host, Interface: 00, Revision: 08 0x000c: BIST: 00, Header Type: 00, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR empty (00000000) 0x0014: BAR empty (00000000) 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR empty (00000000) 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 17aa Product ID: 225c 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 00 Line: 00 Min Gnt: 00 Max Lat: 00 0x00e0: Capability 0x09: Vendor Specific 0:2:0: Intel UHD Graphics 620 0x0000: Vendor ID: 8086, Product ID: 5917 0x0004: Command: 0007, Status: 0010 0x0008: Class: 03 Display, Subclass: 00 VGA, Interface: 00, Revision: 07 0x000c: BIST: 00, Header Type: 00, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR mem 64bit addr: 0x0000002ffe000000/0x01000000 0x0018: BAR mem prefetchable 64bit addr: 0x00000000c0000000/0x20000000 0x0020: BAR io addr: 0x0000e000/0x0040 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 17aa Product ID: 225c 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 01 Line: 0b Min Gnt: 00 Max Lat: 00 0x0040: Capability 0x09: Vendor Specific 0x0070: Capability 0x10: PCI Express 0x0100: Enhanced Capability 0x1b: Process Address Space ID 0x0200: Enhanced Capability 0x0f: Address Translation Services 0x0300: Enhanced Capability 0x13: Page Request Interface 0x00ac: Capability 0x05: Message Signalled Interrupts (MSI) Enabled: yes 0x00d0: Capability 0x01: Power Management State: D0 0:4:0: Intel Core 6G Thermal 0x0000: Vendor ID: 8086, Product ID: 1903 0x0004: Command: 0000, Status: 0090 0x0008: Class: 11 DASP, Subclass: 80 Miscellaneous, Interface: 00, Revision: 08 0x000c: BIST: 00, Header Type: 00, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR mem 64bit addr: 0x0000002fff010000/0x00008000 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR empty (00000000) 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 17aa Product ID: 225c 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 01 Line: ff Min Gnt: 00 Max Lat: 00 0x0090: Capability 0x05: Message Signalled Interrupts (MSI) Enabled: no 0x00d0: Capability 0x01: Power Management State: D0 0x00e0: Capability 0x09: Vendor Specific 0:8:0: Intel Core GMM 0x0000: Vendor ID: 8086, Product ID: 1911 0x0004: Command: 0000, Status: 0010 0x0008: Class: 08 System, Subclass: 80 Miscellaneous, Interface: 00, Revision: 00 0x000c: BIST: 00, Header Type: 00, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR mem 64bit addr: 0x0000002fff01f000/0x00001000 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR empty (00000000) 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 17aa Product ID: 225c 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 01 Line: ff Min Gnt: 00 Max Lat: 00 0x0090: Capability 0x05: Message Signalled Interrupts (MSI) Enabled: no 0x00dc: Capability 0x01: Power Management State: D0 0x00f0: Capability 0x13: PCI Advanced Features 0:20:0: Intel 100 Series xHCI 0x0000: Vendor ID: 8086, Product ID: 9d2f 0x0004: Command: 0006, Status: 0290 0x0008: Class: 0c Serial Bus, Subclass: 03 USB, Interface: 30, Revision: 21 0x000c: BIST: 00, Header Type: 80, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR mem 64bit addr: 0x00000000e0220000/0x00010000 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR empty (00000000) 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 17aa Product ID: 225c 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 01 Line: ff Min Gnt: 00 Max Lat: 00 0x0070: Capability 0x01: Power Management State: D0 0x0080: Capability 0x05: Message Signalled Interrupts (MSI) Enabled: yes 0:20:2: Intel 100 Series Thermal 0x0000: Vendor ID: 8086, Product ID: 9d31 0x0004: Command: 0006, Status: 0010 0x0008: Class: 11 DASP, Subclass: 80 Miscellaneous, Interface: 00, Revision: 21 0x000c: BIST: 00, Header Type: 00, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR mem 64bit addr: 0x0000002fff01e000/0x00001000 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR empty (00000000) 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 17aa Product ID: 225c 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 03 Line: ff Min Gnt: 00 Max Lat: 00 0x0050: Capability 0x01: Power Management State: D0 0x0080: Capability 0x05: Message Signalled Interrupts (MSI) Enabled: no 0:22:0: Intel 100 Series MEI 0x0000: Vendor ID: 8086, Product ID: 9d3a 0x0004: Command: 0004, Status: 0010 0x0008: Class: 07 Communications, Subclass: 80 Miscellaneous, Interface: 00, Revision: 21 0x000c: BIST: 00, Header Type: 80, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR mem 64bit addr: 0x0000002fff01d000/0x00001000 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR empty (00000000) 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 17aa Product ID: 225c 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 01 Line: ff Min Gnt: 00 Max Lat: 00 0x0050: Capability 0x01: Power Management State: D0 0x008c: Capability 0x05: Message Signalled Interrupts (MSI) Enabled: no 0:28:0: Intel 100 Series PCIE 0x0000: Vendor ID: 8086, Product ID: 9d10 0x0004: Command: 0007, Status: 0010 0x0008: Class: 06 Bridge, Subclass: 04 PCI, Interface: 00, Revision: f1 0x000c: BIST: 00, Header Type: 81, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR empty (00000000) 0x0014: BAR empty (00000000) 0x0018: Primary Bus: 0, Secondary Bus: 2, Subordinate Bus: 2, Secondary Latency Timer: 00 0x001c: I/O Base: f0, I/O Limit: 00, Secondary Status: 2000 0x0020: Memory Base: e010, Memory Limit: e010 0x0024: Prefetch Memory Base: fff1, Prefetch Memory Limit: 0001 0x0028: Prefetch Memory Base Upper 32 Bits: ffffffff 0x002c: Prefetch Memory Limit Upper 32 Bits: 00000000 0x0030: I/O Base Upper 16 Bits: 0000, I/O Limit Upper 16 Bits: 0000 0x0038: Expansion ROM Base Address: 00000000 0x003c: Interrupt Pin: 01, Line: ff, Bridge Control: 0000 0x0040: Capability 0x10: PCI Express Link Speed: 2.5 / 8.0 GT/s, Link Width: x1 / x1 0x0100: Enhanced Capability 0x01: Advanced Error Reporting 0x0140: Enhanced Capability 0x0d: Access Control Services 0x0200: Enhanced Capability 0x1e: L1 PM 0x0220: Enhanced Capability 0x19: Secondary PCIe Capability 0x0080: Capability 0x05: Message Signalled Interrupts (MSI) Enabled: yes 0x0090: Capability 0x0d: PCI-PCI 0x00a0: Capability 0x01: Power Management State: D0 0:28:4: Intel 100 Series PCIE 0x0000: Vendor ID: 8086, Product ID: 9d14 0x0004: Command: 0007, Status: 0010 0x0008: Class: 06 Bridge, Subclass: 04 PCI, Interface: 00, Revision: f1 0x000c: BIST: 00, Header Type: 81, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR empty (00000000) 0x0014: BAR empty (00000000) 0x0018: Primary Bus: 0, Secondary Bus: 4, Subordinate Bus: 4, Secondary Latency Timer: 00 0x001c: I/O Base: f0, I/O Limit: 00, Secondary Status: 2000 0x0020: Memory Base: e000, Memory Limit: e000 0x0024: Prefetch Memory Base: fff1, Prefetch Memory Limit: 0001 0x0028: Prefetch Memory Base Upper 32 Bits: ffffffff 0x002c: Prefetch Memory Limit Upper 32 Bits: 00000000 0x0030: I/O Base Upper 16 Bits: 0000, I/O Limit Upper 16 Bits: 0000 0x0038: Expansion ROM Base Address: 00000000 0x003c: Interrupt Pin: 01, Line: ff, Bridge Control: 0000 0x0040: Capability 0x10: PCI Express Link Speed: 5.0 / 8.0 GT/s, Link Width: x4 / x4 0x0100: Enhanced Capability 0x01: Advanced Error Reporting 0x0140: Enhanced Capability 0x0d: Access Control Services 0x0200: Enhanced Capability 0x1e: L1 PM 0x0220: Enhanced Capability 0x19: Secondary PCIe Capability 0x0080: Capability 0x05: Message Signalled Interrupts (MSI) Enabled: yes 0x0090: Capability 0x0d: PCI-PCI 0x00a0: Capability 0x01: Power Management State: D0 0:31:0: Intel 200 Series LPC 0x0000: Vendor ID: 8086, Product ID: 9d4e 0x0004: Command: 0007, Status: 0200 0x0008: Class: 06 Bridge, Subclass: 01 ISA, Interface: 00, Revision: 21 0x000c: BIST: 00, Header Type: 80, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR empty (00000000) 0x0014: BAR empty (00000000) 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR empty (00000000) 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 17aa Product ID: 225c 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 00 Line: 00 Min Gnt: 00 Max Lat: 00 0:31:2: Intel 100 Series PMC 0x0000: Vendor ID: 8086, Product ID: 9d21 0x0004: Command: 0000, Status: 0000 0x0008: Class: 05 Memory, Subclass: 80 Miscellaneous, Interface: 00, Revision: 21 0x000c: BIST: 00, Header Type: 80, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR mem 32bit addr: 0xe0230000/0x00004000 0x0014: BAR empty (00000000) 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR empty (00000000) 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 17aa Product ID: 225c 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 00 Line: 00 Min Gnt: 00 Max Lat: 00 0:31:3: Intel 200 Series HD Audio 0x0000: Vendor ID: 8086, Product ID: 9d71 0x0004: Command: 0006, Status: 0010 0x0008: Class: 04 (unknown), Subclass: 03 (unknown), Interface: 80, Revision: 21 0x000c: BIST: 00, Header Type: 00, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR mem 64bit addr: 0x0000002fff018000/0x00004000 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR mem 64bit addr: 0x0000002fff000000/0x00010000 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 17aa Product ID: 225c 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 01 Line: ff Min Gnt: 00 Max Lat: 00 0x0050: Capability 0x01: Power Management State: D0 0x0060: Capability 0x05: Message Signalled Interrupts (MSI) Enabled: yes 0:31:4: Intel 100 Series SMBus 0x0000: Vendor ID: 8086, Product ID: 9d23 0x0004: Command: 0001, Status: 0280 0x0008: Class: 0c Serial Bus, Subclass: 05 SMBus, Interface: 00, Revision: 21 0x000c: BIST: 00, Header Type: 00, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR mem 64bit addr: 0x0000002fff01c000/0x00000100 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR io addr: 0x0000efa0/0x0020 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 17aa Product ID: 225c 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 01 Line: ff Min Gnt: 00 Max Lat: 00 0:31:6: Intel I219-LM 0x0000: Vendor ID: 8086, Product ID: 15d7 0x0004: Command: 0006, Status: 0010 0x0008: Class: 02 Network, Subclass: 00 Ethernet, Interface: 00, Revision: 21 0x000c: BIST: 00, Header Type: 00, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR mem 32bit addr: 0xe0200000/0x00020000 0x0014: BAR empty (00000000) 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR empty (00000000) 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 17aa Product ID: 225c 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 01 Line: ff Min Gnt: 00 Max Lat: 00 0x00c8: Capability 0x01: Power Management State: D0 0x00d0: Capability 0x05: Message Signalled Interrupts (MSI) Enabled: yes 0x00e0: Capability 0x13: PCI Advanced Features 2:0:0: Intel Dual Band Wireless-AC 8265 0x0000: Vendor ID: 8086, Product ID: 24fd 0x0004: Command: 0006, Status: 0010 0x0008: Class: 02 Network, Subclass: 80 Miscellaneous, Interface: 00, Revision: 78 0x000c: BIST: 00, Header Type: 00, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR mem 64bit addr: 0x00000000e0100000/0x00002000 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR empty (00000000) 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 8086 Product ID: 0010 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 01 Line: ff Min Gnt: 00 Max Lat: 00 0x00c8: Capability 0x01: Power Management State: D0 0x00d0: Capability 0x05: Message Signalled Interrupts (MSI) Enabled: yes 0x0040: Capability 0x10: PCI Express Link Speed: 2.5 / 2.5 GT/s, Link Width: x1 / x1 0x0100: Enhanced Capability 0x01: Advanced Error Reporting 0x0140: Enhanced Capability 0x03: Device Serial Number Serial Number: 983b8fffffef6bef 0x014c: Enhanced Capability 0x18: Latency Tolerance Reporting 0x0154: Enhanced Capability 0x1e: L1 PM 4:0:0: Samsung SM981/PM981 NVMe 0x0000: Vendor ID: 144d, Product ID: a808 0x0004: Command: 0006, Status: 0010 0x0008: Class: 01 Mass Storage, Subclass: 08 NVM, Interface: 02, Revision: 00 0x000c: BIST: 00, Header Type: 00, Latency Timer: 00, Cache Line Size: 00 0x0010: BAR mem 64bit addr: 0x00000000e0000000/0x00004000 0x0018: BAR empty (00000000) 0x001c: BAR empty (00000000) 0x0020: BAR empty (00000000) 0x0024: BAR empty (00000000) 0x0028: Cardbus CIS: 00000000 0x002c: Subsystem Vendor ID: 144d Product ID: a801 0x0030: Expansion ROM Base Address: 00000000 0x0038: 00000000 0x003c: Interrupt Pin: 01 Line: ff Min Gnt: 00 Max Lat: 00 0x0040: Capability 0x01: Power Management State: D0 0x0050: Capability 0x05: Message Signalled Interrupts (MSI) Enabled: no 0x0070: Capability 0x10: PCI Express Link Speed: 5.0 / 8.0 GT/s, Link Width: x4 / x4 0x0100: Enhanced Capability 0x01: Advanced Error Reporting 0x0148: Enhanced Capability 0x03: Device Serial Number Serial Number: 0000000000000000 0x0158: Enhanced Capability 0x04: Power Budgeting 0x0168: Enhanced Capability 0x19: Secondary PCIe Capability 0x0188: Enhanced Capability 0x18: Latency Tolerance Reporting 0x0190: Enhanced Capability 0x1e: L1 PM 0x00b0: Capability 0x11: Extended Message Signalled Interrupts (MSI-X) Enabled: yes; table size 33 (BAR 0:12288)