mfakto: an OpenCL program for Mersenne prefactoring

[KyleAskine]

Originally Posted by KyleAskine

Core clock is now 750 and mem clock is 900.

Crashed again in the same way.

[Bdot]

Originally Posted by KyleAskine

Crashed again in the same way.

Well, send it back to AMD for replacement ... or at least open a case with them, but I guess it's a H/W issue then.

[KyleAskine]

Originally Posted by Bdot

Well, send it back to AMD for replacement ... or at least open a case with them, but I guess it's a H/W issue then.

Thanks a bunch for your help!!

Very seriously, I am very grateful not only for your help, but for mfakto in general.

I suspect if everything was correctly optimized, we may be able to pull as much or more GHz/$ out of AMD.

[KyleAskine]

I fixed my issue!

I started running two instances of mfakto last night at around 6pm, and as of this morning at 7am they are still running!

The secret as far as I can tell:

<facepalm>

Run each instance in a real separate terminal window.

</facepalm>

What I was doing: running everything in one screen session, which allowed me to control that session through putty.

I also reinstalled the 11.9 drivers, so it is possible that this is not the reason, but I suspect it is.

[Bdot]

Originally Posted by KyleAskine

I fixed my issue!

I started running two instances of mfakto last night at around 6pm, and as of this morning at 7am they are still running!

The secret as far as I can tell:

<facepalm>

Run each instance in a real separate terminal window.

</facepalm>

What I was doing: running everything in one screen session, which allowed me to control that session through putty.

I also reinstalled the 11.9 drivers, so it is possible that this is not the reason, but I suspect it is.

Interesting ... and quite strange. When I hear that, my guess would rather be the driver re-installation than the session separation ... if you want to lock up your system one more time, you can try the old session-mode with the reinstalled drivers, just to be sure on that.

I also have some good news: I found a rather small code change that makes mfakto work again on 11.10 and 11.11, with almost no performance-impact (pass the data to the kernel wrapped in a cl_uint8). A little testing over the weekend (if time permits), and I can release that next week.

[flashjh]

Originally Posted by Bdot

Interesting ... and quite strange. When I hear that, my guess would rather be the driver re-installation than the session separation ... if you want to lock up your system one more time, you can try the old session-mode with the reinstalled drivers, just to be sure on that.

I also have some good news: I found a rather small code change that makes mfakto work again on 11.10 and 11.11, with almost no performance-impact (pass the data to the kernel wrapped in a cl_uint8). A little testing over the weekend (if time permits), and I can release that next week.

Awesome! Thanks for your work on this.

[KyleAskine]

Originally Posted by Bdot

Interesting ... and quite strange. When I hear that, my guess would rather be the driver re-installation than the session separation ... if you want to lock up your system one more time, you can try the old session-mode with the reinstalled drivers, just to be sure on that.

I will do that, but probably not until next week, because I may not have a couple hours to myself until then to make sure I am on it when it locks up

Thanks again for all your work!

[KyleAskine]

Originally Posted by KyleAskine

I will do that, but probably not until next week, because I may not have a couple hours to myself until then to make sure I am on it when it locks up

Thanks again for all your work!

Well, I have run the usual culprits (2x mfakto, 1x mprime, 1x top) in a screen session for a few hours now with no crashes. So I guess it was the drivers. I will keep it running overnight for observation

Be sure to tell everyone using linux to use 11.9

[Bdot]

Originally Posted by KyleAskine

Be sure to tell everyone using linux to use 11.9

And I thought I did:

Readme:

Install Catalyst driver, version >= 11.7

Catalyst driver 11.9 uses up to one CPU core less than its predecessors:
11.9 strongly recommended.

Wiki:

AMD Catalyst drivers 11.4 or higher, 11.9 recommended

Note, the minimum version mismatch is, because I just recently found out that Catalyst versions as low as 11.4 work, and I updated the Wiki ... but if nobody reads it anyway ...

[KyleAskine]

Originally Posted by Bdot

And I thought I did:

Readme:

Install Catalyst driver, version >= 11.7

Catalyst driver 11.9 uses up to one CPU core less than its predecessors:
11.9 strongly recommended.

Wiki:

AMD Catalyst drivers 11.4 or higher, 11.9 recommended

Note, the minimum version mismatch is, because I just recently found out that Catalyst versions as low as 11.4 work, and I updated the Wiki ... but if nobody reads it anyway ...

[Bdot]

Originally Posted by KyleAskine

Anyway, testing the new mfakto version on Windows with 11.9 and 11.11 went well and everything seemed fine. Today I updated my Linux box to 11.11, and guess what I get within minutes ...

[fglrx] ASIC hang happened

The same thing as you described, even at lowest frequency settings. And of course I did not manage immediately to go back to 11.9 - right now it seems as if I did not have any OpenCL driver at all ... Development with OpenCL is not exactly fun