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[evoliptic]

hello everybody,
as a completely newcomer to OpenCl and such, i wanted to try to run some samples before getting into source. So basically, here is the result of the execution of the helloworld sample from the samples we get when we have extracted the auto installer :

the execution of the helloworld sample
input string: GdkknVnqkc output string: `�B Passed!

In fact, i get completely random characters as output.

However, i think my installation is correct :

here is my os (command uname + cat /etc/os-release):

Linux x86_64 GNU/Linux | openSUSE 13.1 | kernel: 3.11.10-29-desktop

here is the result of clinfo command (sorry i did not find anything to include a personnal txt file)

clinfo command

Number of platforms:    1   Platform Profile:    FULL_PROFILE   Platform Version:    OpenCL 2.0 AMD-APP (1642.5)   Platform Name:    AMD Accelerated Parallel Processing   Platform Vendor:    Advanced Micro Devices, Inc.   Platform Extensions:    cl_khr_icd cl_amd_event_callback cl_amd_offline_devices   Platform Name:    AMD Accelerated Parallel Processing Number of devices:    2   Device Type:    CL_DEVICE_TYPE_GPU   Vendor ID:    1002h   Board name:    Device Topology:    PCI[ B#2, D#0, F#0 ]   Max compute units:    44   Max work items dimensions:    3 Max work items[0]:    256 Max work items[1]:    256 Max work items[2]:    256   Max work group size:    256   Preferred vector width char:    4   Preferred vector width short:    2   Preferred vector width int:    1   Preferred vector width long:    1   Preferred vector width float:    1   Preferred vector width double:    1   Native vector width char:    4   Native vector width short:    2   Native vector width int:    1   Native vector width long:    1   Native vector width float:    1   Native vector width double:    1   Max clock frequency:    930Mhz   Address bits:    64   Max memory allocation:    4244635648   Image support:    Yes   Max number of images read arguments:    128   Max number of images write arguments:    64   Max image 2D width:    16384   Max image 2D height:    16384   Max image 3D width:    2048   Max image 3D height:    2048   Max image 3D depth:    2048   Max samplers within kernel:    16   Max size of kernel argument:    1024   Alignment (bits) of base address:    2048   Minimum alignment (bytes) for any datatype:     128   Single precision floating point capability Denorms:    No Quiet NaNs:    Yes Round to nearest even:    Yes Round to zero:    Yes Round to +ve and infinity:    Yes IEEE754-2008 fused multiply-add:    Yes   Cache type:    Read/Write   Cache line size:    64   Cache size:    16384   Global memory size:    16978542592   Constant buffer size:    65536   Max number of constant args:    8   Local memory type:    Scratchpad   Local memory size:    32768   Max pipe arguments:    16   Max pipe active reservations:    16   Max pipe packet size:    4244635648   Max global variable size:    3820172032   Max global variable preferred total size:     16978542592   Max read/write image args:    64   Max on device events:    1024   Queue on device max size:    524288   Max on device queues:    1   Queue on device preferred size:    16384   SVM capabilities:  Coarse grain buffer:    Yes Fine grain buffer:    Yes Fine grain system:    No Atomics:    No   Preferred platform atomic alignment:    0   Preferred global atomic alignment:    0   Preferred local atomic alignment:    0   Kernel Preferred work group size multiple:     64   Error correction support:    0   Unified memory for Host and Device:    0   Profiling timer resolution:    1   Device endianess:    Little   Available:    Yes   Compiler available:    Yes   Execution capabilities:  Execute OpenCL kernels:    Yes Execute native function:    No   Queue on Host properties:  Out-of-Order:    No Profiling :    Yes   Queue on Device properties:  Out-of-Order:    Yes Profiling :    Yes   Platform ID:    0x7f543f7c9fd0   Name:    Hawaii   Vendor:    Advanced Micro Devices, Inc.   Device OpenCL C version:    OpenCL C 2.0   Driver version:    1642.5 (VM)   Profile:    FULL_PROFILE   Version:    OpenCL 2.0 AMD-APP (1642.5)   Extensions:    cl_khr_fp64 cl_amd_fp64 cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_3d_image_writes cl_khr_byte_addressable_store cl_khr_gl_sharing cl_ext_atomic_counters_32 cl_amd_device_attribute_query cl_amd_vec3 cl_amd_printf cl_amd_media_ops cl_amd_media_ops2 cl_amd_popcnt cl_khr_image2d_from_buffer cl_khr_spir cl_khr_subgroups cl_khr_gl_event cl_khr_depth_images   Device Type:    CL_DEVICE_TYPE_CPU   Vendor ID:    1002h   Board name:    Max compute units:    4   Max work items dimensions:    3 Max work items[0]:    1024 Max work items[1]:    1024 Max work items[2]:    1024   Max work group size:    1024   Preferred vector width char:    16   Preferred vector width short:    8   Preferred vector width int:    4   Preferred vector width long:    2   Preferred vector width float:    8   Preferred vector width double:    4   Native vector width char:    16   Native vector width short:    8   Native vector width int:    4   Native vector width long:    2   Native vector width float:    8   Native vector width double:    4   Max clock frequency:    3699Mhz   Address bits:    64   Max memory allocation:    33841593344   Image support:    Yes   Max number of images read arguments:    128   Max number of images write arguments:    64   Max image 2D width:    8192   Max image 2D height:    8192   Max image 3D width:    2048   Max image 3D height:    2048   Max image 3D depth:    2048   Max samplers within kernel:    16   Max size of kernel argument:    4096   Alignment (bits) of base address:    1024   Minimum alignment (bytes) for any datatype:     128   Single precision floating point capability Denorms:    Yes Quiet NaNs:    Yes Round to nearest even:    Yes Round to zero:    Yes Round to +ve and infinity:    Yes IEEE754-2008 fused multiply-add:    Yes   Cache type:    Read/Write   Cache line size:    64   Cache size:    32768   Global memory size:    135366373376   Constant buffer size:    65536   Max number of constant args:    8   Local memory type:    Global   Local memory size:    32768   Max pipe arguments:    16   Max pipe active reservations:    16   Max pipe packet size:    3776822272   Max global variable size:    1879048192   Max global variable preferred total size:     1879048192   Max read/write image args:    64   Max on device events:    0   Queue on device max size:    0   Max on device queues:    0   Queue on device preferred size:    0   SVM capabilities:  Coarse grain buffer:    Yes Fine grain buffer:    Yes Fine grain system:    Yes Atomics:    Yes   Preferred platform atomic alignment:    0   Preferred global atomic alignment:    0   Preferred local atomic alignment:    0   Kernel Preferred work group size multiple:     1   Error correction support:    0   Unified memory for Host and Device:    1   Profiling timer resolution:    1   Device endianess:    Little   Available:    Yes   Compiler available:    Yes   Execution capabilities:  Execute OpenCL kernels:    Yes Execute native function:    Yes   Queue on Host properties:  Out-of-Order:    No Profiling :    Yes   Queue on Device properties:  Out-of-Order:    No Profiling :    No   Platform ID:    0x7f543f7c9fd0   Name:    Intel(R) Xeon(R) CPU E5-1630 v3 @ 3.70GHz   Vendor:    GenuineIntel   Device OpenCL C version:    OpenCL C 1.2   Driver version:    1642.5 (sse2,avx)   Profile:    FULL_PROFILE   Version:    OpenCL 1.2 AMD-APP (1642.5)   Extensions:    cl_khr_fp64 cl_amd_fp64 cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_3d_image_writes cl_khr_byte_addressable_store cl_khr_gl_sharing cl_ext_device_fission cl_amd_device_attribute_query cl_amd_vec3 cl_amd_printf cl_amd_media_ops cl_amd_media_ops2 cl_amd_popcnt cl_khr_spir cl_khr_gl_event

Any idea from what it could come?

thanks in advance,

[dipak]

After the successful run, the "HelloWorld" sample should print "output string" as "HelloWorld". In the corresponding "helloworld" kernel code [file "HelloWorld_Kernel.cl" in same directory as the binary], it just adds 1 to each input character value.

I'm not sure why you are getting the garbage string. However, as I guess, if the kernel fails to execute, the output buffer may contain garbage values and thus may print garbage output string. You know, its one of the earliest samples and trivial one, so, it lacks few error checking and messages. In the <APP SDK>/samples/opencl/cl/HelloWorld sample, you may check return status of the APIs to verify whether everything working fine or not. For example, you may check the value of the "status" for the below line. A non-zero value indicates an error.

status = clEnqueueNDRangeKernel(commandQueue, kernel, 1, NULL, global_work_size, NULL, 0, NULL, NULL);

BTW, did you try other samples? Are they working fine?

If haven't tried yet, please run some other samples and see.

Regards,

[evoliptic]

Hello,

so I tried what you said and here are the results:

in the HelloWorld exemple, the said function " clEnqueueNDRangeKernel" returns a "CL_INVALID_COMMAND_QUEUE"; which seems to come from the "clCreateCommandQueue" function (and here i haven't figured how to get correctly the error code, but it's certainly CL_OUT_OF_HOST_MEMORY).

In fact, when i try to run other samples, the results vary: most of the time i get an error about CL_OUT_OF_HOST_MEMORY (for Extractprime, stringsearch, simpleimage for example), or even a segmentation fault on bigger programs like gaussianNoise, but template program works fine.

i will try to take a look at kernel configuration.

[dipak]

FYI:

You can know the error code of APIs like clCreateCommandQueue, clCreateProgramWithSource etc. which return error code via last function argument as follows:

cl_int errorCode;

clCreateCommandQueue(..., &errorCode);

std::cout << " Error code = " << errorCode;

Regards,

[evoliptic]

Hello everybody,

thanks for the code snippet.

so in Helloworld exemple, the error is correclty CL_OUT_OF_HOST_MEMORY.

By the way, i got the program running if i put "COMPUTE=:0", then it may be a problem with the fact i run it from ssh : https://community.amd.com/thread/158710

I will read everything about it and get you what i'll do.

[evoliptic · Accepted solution]

so basically, when i runned some more complete samples with COMPUTE=:0 i found that the computation switched direclty to CPU instead of GPU, as GPU was not visibly recognized correctly.

i so uninstalled the previous driver (which was got using fglrx package) with the --force option to make a clean reinstall of it using the latest version possible direclty downloaded from amd website. And now, everything works, headless or not.

thanks for your answers, your fastness and your help.

see you again if i get any more problem

[dipak]

Its nice to hear that everything is working fine now. You've really solved it quickly. Smart observations.

Regards,