Question about checkres in testing_sgehrd

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Question about checkres in testing_sgehrd

Postby cz0397 » Tue Mar 26, 2013 8:24 am

Hello. Today, I run the file testing_sgehrd. I find some question with it.
First, the result does not show the error. Following is the result:
Code: Select all
./testing_sgehrd -N 6000
MAGMA 1.3.0
device 0: GeForce 405, 1402.0 MHz clock, 511.6 MB memory, capability 1.2
  testing_sgehrd -N 6000

  N    CPU GFlop/s    GPU GFlop/s   |A-QHQ'|/N|A|  |I-QQ'|/N
=============================================================
 6000     26.44           9.56


Next, I go to see the cpp file, and find such sentence:

checkres = getenv("MAGMA_TESTINGS_CHECK") != NULL;

I think checkres get an unproper value, which cause the following step wrong.

Code: Select all
if ( checkres ) {
            printf("%5d    %6.2f         %6.2f      %e %e\n",
                   (int) N, cpu_perf, gpu_perf,
                   result[0]*eps, result[1]*eps );
        } else {
            printf("%5d    %6.2f         %6.2f\n",
                   (int) N, cpu_perf, gpu_perf );
        }

Since the result comes out incompletely, then I wonder whether the computing progress goes wrong. I see 4 points using checkres as judging standard.

Finally, I want to know whether this program can be debuged by GDB.

Thank you for helping!
cz0397
 
Posts: 15
Joined: Tue Feb 26, 2013 10:22 pm

Re: Question about checkres in testing_sgehrd

Postby mgates3 » Wed Mar 27, 2013 4:25 pm

Normally, checkres is false, and the error is not computed, because it takes a long time. In order to report the error, you need to set the environment variable $MAGMA_TESTINGS_CHECK. That is:

for csh:
setenv MAGMA_TESTINGS_CHECK
./testing_sgehrd

for bash:
export MAGMA_TESTINGS_CHECK=1
./testing_sgehrd

Yes, you can use gdb, but it won't debug the CUDA code itself, only the code running on the CPU.

-mark
mgates3
 
Posts: 442
Joined: Fri Jan 06, 2012 2:13 pm

Re: Question about checkres in testing_sgehrd

Postby cz0397 » Fri Mar 29, 2013 12:41 am

Year! It's OK now. Thanks a lot!
cz0397
 
Posts: 15
Joined: Tue Feb 26, 2013 10:22 pm


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