Re: X11 intermittently blanking

2020-10-13 Thread Laurence Tratt 
On Fri, Oct 02, 2020 at 03:20:36PM +0100, Laurence Tratt wrote:

>> For the past couple of weeks I've been encountering a weird problem on
>> -current amd64 -- my screen intermittently blanks for around 2-4 seconds
>> when running xorg. At first I thought this was a hardware problem (the
>> machine isn't a spring chicken), but then ffmpeg caught the blanking while
>> I was doing a screencast (i.e. the recording of the xorg part of things
>> goes entirely blank for a couple of seconds), so it seems to be a software
>> problem.
>>
>> Unfortunately I can't seem to find any obvious trigger. It seems to happen
>> more often when the machine is under heavy load, but sometimes it happens
>> under light load. Frankly, I don't have any real idea *what* could be
>> causing it, and I'm hoping that someone else might have seen this, and
>> perhaps have been equally baffled as to the cause!
> I have now found a semi-reliable way of triggering this with the following
> ffmpeg command on a decent length video file:
>
>   ffmpeg -i  -c:a flac out.flac
>
> The blanking effect is not consistent or continuous: sometimes the display
> will blank every few seconds, sometimes it might go 30 seconds without
> doing so.
>
> I'm running on a 4 core machine, and this task maxes out all 4 cores.
> Interestingly, however, other tasks which use all 4 cores do not cause the
> display blanking problem as often. I don't know what ffmpeg is doing
> differently, other than 'top' shows that it's often 'fsleep'ing (which may
> well be completely irrelevant to the problem I'm seeing).

For the record, I've not had this problem in the last week or so --
hopefully it's disappeared for good!


Laurie

Re: X11 intermittently blanking

2020-10-02 Thread Laurence Tratt 
On Wed, Sep 30, 2020 at 10:30:57PM +0100, Laurence Tratt wrote:

> For the past couple of weeks I've been encountering a weird problem on
> -current amd64 -- my screen intermittently blanks for around 2-4 seconds
> when running xorg. At first I thought this was a hardware problem (the
> machine isn't a spring chicken), but then ffmpeg caught the blanking while
> I was doing a screencast (i.e. the recording of the xorg part of things
> goes entirely blank for a couple of seconds), so it seems to be a software
> problem.
>
> Unfortunately I can't seem to find any obvious trigger. It seems to happen
> more often when the machine is under heavy load, but sometimes it happens
> under light load. Frankly, I don't have any real idea *what* could be
> causing it, and I'm hoping that someone else might have seen this, and
> perhaps have been equally baffled as to the cause!

I have now found a semi-reliable way of triggering this with the following
ffmpeg command on a decent length video file:

  ffmpeg -i  -c:a flac out.flac

The blanking effect is not consistent or continuous: sometimes the display
will blank every few seconds, sometimes it might go 30 seconds without doing
so.

I'm running on a 4 core machine, and this task maxes out all 4 cores.
Interestingly, however, other tasks which use all 4 cores do not cause the
display blanking problem as often. I don't know what ffmpeg is doing
differently, other than 'top' shows that it's often 'fsleep'ing (which may
well be completely irrelevant to the problem I'm seeing).


Laurie

X11 intermittently blanking

2020-09-30 Thread Laurence Tratt 
For the past couple of weeks I've been encountering a weird problem on
-current amd64 -- my screen intermittently blanks for around 2-4 seconds
when running xorg. At first I thought this was a hardware problem (the
machine isn't a spring chicken), but then ffmpeg caught the blanking while I
was doing a screencast (i.e. the recording of the xorg part of things goes
entirely blank for a couple of seconds), so it seems to be a software
problem.

Unfortunately I can't seem to find any obvious trigger. It seems to happen
more often when the machine is under heavy load, but sometimes it happens
under light load. Frankly, I don't have any real idea *what* could be causing
it, and I'm hoping that someone else might have seen this, and perhaps have
been equally baffled as to the cause!


Laurie



OpenBSD 6.8 (GENERIC.MP) #94: Tue Sep 29 00:13:21 MDT 2020
dera...@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC.MP
real mem = 17028239360 (16239MB)
avail mem = 16497115136 (15732MB)
random: good seed from bootblocks
mpath0 at root
scsibus0 at mpath0: 256 targets
mainbus0 at root
bios0 at mainbus0: SMBIOS rev. 3.0 @ 0xc320 (89 entries)
bios0: vendor American Megatrends Inc. version "3805" date 05/16/2018
bios0: ASUSTeK COMPUTER INC. Z170M-PLUS
acpi0 at bios0: ACPI 6.1
acpi0: sleep states S0 S3 S4 S5
acpi0: tables DSDT FACP APIC FPDT BGRT MCFG SSDT FIDT SSDT SSDT HPET SSDT SSDT 
UEFI SSDT LPIT WSMT SSDT SSDT DBGP DBG2
acpi0: wakeup devices PEG0(S4) PEGP(S4) PEG1(S4) PEGP(S4) PEG2(S4) PEGP(S4) 
SIO1(S3) UAR1(S4) RP09(S4) PXSX(S4) RP10(S4) PXSX(S4) RP11(S4) PXSX(S4) 
RP12(S4) PXSX(S4) [...]
acpitimer0 at acpi0: 3579545 Hz, 24 bits
acpimadt0 at acpi0 addr 0xfee0: PC-AT compat
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz, 4121.53 MHz, 06-5e-03
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,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,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, IBE
cpu1 at mainbus0: apid 2 (application processor)
cpu1: Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz, 4120.01 MHz, 06-5e-03
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,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,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) i7-6700K CPU @ 4.00GHz, 4120.01 MHz, 06-5e-03
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,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,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) i7-6700K CPU @ 4.00GHz, 4120.01 MHz, 06-5e-03
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,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,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 0xfec0, version 20, 120 pins
acpimcfg0 at acpi0
acpimcfg0: addr 0xf800, bus 0-63
acpihpet0 at acpi0: 2399 Hz
acpiprt0 at acpi0: bus 0 (PCI0)
acpiprt1 at acpi0: bus -1 (PEG0)
acpiprt2 at acpi0: bus -1 (PEG1)
acpiprt3 at acpi0: bus -1 (PEG2)
acpiprt4 at acpi0: bus 4 (RP09)
acpiprt5 at