gpuOwL: an OpenCL program for Mersenne primality testing - Page 96

2019-04-07, 13:14

Quote:

Originally Posted by SELROC

It may be my negligence, I was running kernel 5.0.5 but with an outdated initramfs. After updating initramfs the error is not occurring.

I must note that the error (zero residue) has appeared for the first time to me with the radeon VII.

preda · 2019-04-07, 20:14

Quote:

Originally Posted by SELROC

I must note that the error (zero residue) has appeared for the first time to me with the radeon VII.

Yes, I have no idea why it happens. I'm also using an R7 now, I'll keep an eye on it and let you know if I see the same.

M344587487 · 2019-04-07, 20:32

I've been running an R7 24/7 at 1.03V, 50mV under stock voltage since testing it a few weeks ago. No crashes or suspicious results, the only issue was a corrupted checkpoint after a power cut forced a rollback to the latest 20M checkpoint.

2019-04-08, 05:44

Quote:

Originally Posted by M344587487

I've been running an R7 24/7 at 1.03V, 50mV under stock voltage since testing it a few weeks ago. No crashes or suspicious results, the only issue was a corrupted checkpoint after a power cut forced a rollback to the latest 20M checkpoint.

That is another story, which happened to me also: hit ctrl-C and cut off the power without waiting. The result is a zero-length checkpoint, invalid.

2019-04-08, 05:45

Quote:

Originally Posted by preda

Yes, I have no idea why it happens. I'm also using an R7 now, I'll keep an eye on it and let you know if I see the same.

Thanks. I keep an eye to see if it happens again.

preda · 2019-04-08, 10:33

Quote:

Originally Posted by M344587487

I've been running an R7 24/7 at 1.03V, 50mV under stock voltage since testing it a few weeks ago. No crashes or suspicious results, the only issue was a corrupted checkpoint after a power cut forced a rollback to the latest 20M checkpoint.

There is also another checkpoint, NNNNNN-prev.owl, which likely should not be corrupted at the same time as the main checkpoint. But the recovery from it is not automatic (i.e. you have to manually rename it).

preda · 2019-04-08, 10:36

Quote:

Originally Posted by SELROC

That is another story, which happened to me also: hit ctrl-C and cut off the power without waiting. The result is a zero-length checkpoint, invalid.

Maybe recover from the "previous" checkpoint, -prev.owl, in such a situation.

2019-04-08, 10:37

Quote:

Originally Posted by preda

Maybe recover from the "previous" checkpoint, -prev.owl, in such a situation.

Yes I did.

M344587487 · 2019-04-08, 10:41

Tried it and it did the same thing as the normal checkpoint. Sorry I can't remember the exact details but think the initial restart printed out half a dozen lines before erroring, could that have been enough to overwrite a good prev.owl checkpoint with a bad one before I got to it?

preda · 2019-04-08, 11:45

Quote:

Originally Posted by M344587487

Tried it and it did the same thing as the normal checkpoint. Sorry I can't remember the exact details but think the initial restart printed out half a dozen lines before erroring, could that have been enough to overwrite a good prev.owl checkpoint with a bad one before I got to it?

before writing a checkpoint, GPUowl always does a check, and only writes anything if the check succeeds. So in a bad state nothing should be written. At least that's the theory..

OTOH a check is also done on startup/load, so in a bad state it shouldn't even start.

preda · 2019-04-09, 21:39

News:
Added arguments for bypassing worktodo.txt
-prp <exponent>
-pm1 <exponent>

Embedded gpuowl.cl in executable, the .cl file next to the executable is not needed anymore.

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2019-04-07, 20:32	#1048
M344587487 "Composite as Heck" Oct 2017 2²·3²·23 Posts	I've been running an R7 24/7 at 1.03V, 50mV under stock voltage since testing it a few weeks ago. No crashes or suspicious results, the only issue was a corrupted checkpoint after a power cut forced a rollback to the latest 20M checkpoint.

2019-04-08, 10:41	#1054
M344587487 "Composite as Heck" Oct 2017 2²×3²×23 Posts	Tried it and it did the same thing as the normal checkpoint. Sorry I can't remember the exact details but think the initial restart printed out half a dozen lines before erroring, could that have been enough to overwrite a good prev.owl checkpoint with a bad one before I got to it?

2019-04-09, 21:39	#1056
preda "Mihai Preda" Apr 2015 10101011011₂ Posts	News: Added arguments for bypassing worktodo.txt -prp <exponent> -pm1 <exponent> Embedded gpuowl.cl in executable, the .cl file next to the executable is not needed anymore.