mfaktc: a CUDA program for Mersenne prefactoring

[moebius]

Originally Posted by Dubslow

Nuts. Now to fix mine

Do you use Cuda 3.2 just like me?

[Dubslow]

No, you're not using 3.2 anymore. Note the driver/runtime versions. I have the 3.2 IDE installed like you, but mfaktc could never find the /usr/local/cuda/lib, even when LD_LIBRARY_PATH was set properly, so I had to use a workaround to get it to find the right .so file. I'm using the same workaround for .18 and instead it tells me runtime version 0.0, and driver version... well just go check the previous page.

[TheJudger]

Dubslow:

actually I've no clue whats wrong but can you check this:

• which nvidia driver do you have installed? (run e.g. 'nvidia-smi -a')
• did you check 'ldd mfaktc-lin-64' or 'LD_LIBRARY_PATH=./bin ldd mfaktc-lin-64'?

Oliver

[James Heinrich]

Feature request for v0.19:

Can you make it (optionally) write something like "no work left in worktodo.txt" when it runs out of work? I tend to look at the results files for all my computers once a day or so, but I may not always notice when it runs out of work -- a notice in the results file would make it immediately obvious.

[Dubslow]

Originally Posted by TheJudger

Dubslow:

actually I've no clue whats wrong but can you check this:

• which nvidia driver do you have installed? (run e.g. 'nvidia-smi -a')
• did you check 'ldd mfaktc-lin-64' or 'LD_LIBRARY_PATH=./bin ldd mfaktc-lin-64'?

Oliver

bill@Gravemind:~∰∂ nvidia-smi -a

==============NVSMI LOG==============

Timestamp                       : Wed Dec 21 22:24:32 2011

Driver Version                  : 270.41.06

Attached GPUs                   : 1

GPU 0:1:0
    Product Name                : GeForce GTX 460
    Display Mode                : N/A
    Persistence Mode            : Disabled
    Driver Model
        Current                 : N/A
        Pending                 : N/A
    Serial Number               : N/A
    GPU UUID                    : N/A
    Inforom Version
        OEM Object              : N/A
        ECC Object              : N/A
        Power Management Object : N/A
    PCI
        Bus                     : 1
        Device                  : 0
        Domain                  : 0
        Device Id               : E2210DE
        Bus Id                  : 0:1:0
    Fan Speed                   : 40 %
    Memory Usage
        Total                   : 767 Mb
        Used                    : 214 Mb
        Free                    : 552 Mb
    Compute Mode                : Default
    Utilization
        Gpu                     : N/A
        Memory                  : N/A
    Ecc Mode
        Current                 : N/A
        Pending                 : N/A
    ECC Errors
        Volatile
            Single Bit            
                Device Memory   : N/A
                Register File   : N/A
                L1 Cache        : N/A
                L2 Cache        : N/A
                Total           : N/A
            Double Bit            
                Device Memory   : N/A
                Register File   : N/A
                L1 Cache        : N/A
                L2 Cache        : N/A
                Total           : N/A

I realize 270 is very old, but the .run files that NVidia provides to update the drivers have never worked for me; they wind up breaking the GUI. I install the package nvidia-current to fix it. This is Ubuntu 11.04.

bill@Gravemind:~/mfaktc∰∂ LD_LIBRARY_PATH=./lib ldd ./mfaktc-lin-64 
	linux-vdso.so.1 =>  (0x00007fff41fff000)
	libcudart.so.4 => ./lib/libcudart.so.4 (0x00007f51d6ecb000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f51d6b11000)
	libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f51d680a000)
	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f51d6585000)
	libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f51d6381000)
	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f51d6162000)
	librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f51d5f5a000)
	libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f51d5d44000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f51d711f000)

Not sure what to look for here.

Would installing the 4.1 SDK help?

[TheJudger]

Originally Posted by Dubslow

[code]bill@Gravemind:~∰∂ nvidia-smi -a
[...]
Driver Version : 270.41.06
[...]
[code]

Can you try to upgrade the driver: devdriver_4.0_linux_64_270.41.19.run

Originally Posted by Dubslow

Would installing the 4.1 SDK help?

Well, if everything is right the CUDA SDK and CUDA Toolkit is not needed to run the precompiled mfaktc executable. You'll need a proper driver, nothing more.

Oliver

[James Heinrich]

Not sure if I found a bug or did something silly. I was playing around with M252674011 (had 8 known factors, I got excited when I found another one two three, but they were all composites of smaller known factors ). But I ran into this:

no factor for M252674011 from 2^68 to 2^69 [mfaktc 0.18 barrett79_mul32]
WARNING: can't delete the checkpoint file "mfaktc.ckp"
tf(): total time spent: 2m 26.308s

[TheJudger]

Hello James,

you have just discovered a bug. The good news is that it is not critical. I guess because of the short runtime there was no checkpoint written at all...

Oliver

[Bdot]

Originally Posted by TheJudger

Hello James,

you have just discovered a bug. The good news is that it is not critical. I guess because of the short runtime there was no checkpoint written at all...

Oliver

Yes, I get this too if no checkpoints were written. Nothing serious.

[TheJudger]

I've just noticed that the text is wrong, too. Those checkpoint files are no longer named "mfaktc.ckp"...

Oliver

[James Heinrich]

Originally Posted by TheJudger

I've just noticed that the text is wrong, too. Those checkpoint files are no longer named "mfaktc.ckp"...

That's what caught my attention.