The cl_device_svm_capabilities is not an “object”, but only a typedef of a number (particularly, it is just a cl_bitmask, which is a cl_long…)
So querying it is possible with
long svmCapabilities[] = { 0 };
clGetDeviceInfo(device, CL_DEVICE_SVM_CAPABILITIES,
Sizeof.cl_long, Pointer.to(svmCapabilities), null);
With this value, you can do the usual bitwise checks, like
if ((svmCapabilities[0] & CL_DEVICE_SVM_COARSE_GRAIN_BUFFER) != 0)
{
// Yep, coarse grain buffer is available...
}
Here is an example that prints the capabilities of all devices on all platforms (for the platforms that support OpenCL >= 2.0) :
import static org.jocl.CL.*;
import org.jocl.*;
public class DetectSvmCapabilities
{
public static void main(String[] args)
{
// Enable exceptions and subsequently omit error checks in this sample
CL.setExceptionsEnabled(true);
// Obtain the number of platforms
int numPlatformsArray[] = new int[1];
clGetPlatformIDs(0, null, numPlatformsArray);
int numPlatforms = numPlatformsArray[0];
// Obtain all platform IDs
cl_platform_id platforms[] = new cl_platform_id[numPlatforms];
clGetPlatformIDs(platforms.length, platforms, null);
for (cl_platform_id platform : platforms)
{
String platformName = getString(platform, CL_PLATFORM_NAME);
System.out.println("Platform: " + platformName);
float clVersion = getOpenCLVersion(platform);
System.out.println(" CL version: " + clVersion);
if (clVersion < 2.0)
{
System.out.println(" (no SVM support)");
continue;
}
// Obtain the number of devices for the platform
int numDevicesArray[] = new int[1];
clGetDeviceIDs(platform, CL_DEVICE_TYPE_ALL,
0, null, numDevicesArray);
int numDevices = numDevicesArray[0];
// Obtain the all device IDs
cl_device_id allDevices[] = new cl_device_id[numDevices];
clGetDeviceIDs(platform, CL_DEVICE_TYPE_ALL,
numDevices, allDevices, null);
for (cl_device_id currentDevice : allDevices)
{
String deviceName = getString(currentDevice, CL_DEVICE_NAME);
System.out.println(" Device: " + deviceName);
long svmCapabilities[] = { 0 };
clGetDeviceInfo(currentDevice, CL_DEVICE_SVM_CAPABILITIES,
Sizeof.cl_long, Pointer.to(svmCapabilities), null);
String svmCapabilitiesString =
CL.stringFor_cl_device_svm_capabilities(
svmCapabilities[0]);
System.out.println(" SVM capabilities: " +
svmCapabilitiesString);
}
}
}
private static float getOpenCLVersion(cl_platform_id platform)
{
String deviceVersion = getString(platform, CL_PLATFORM_VERSION);
String versionString = deviceVersion.substring(7, 10);
float version = Float.parseFloat(versionString);
return version;
}
private static String getString(cl_device_id device, int paramName)
{
long size[] = new long[1];
clGetDeviceInfo(device, paramName, 0, null, size);
byte buffer[] = new byte[(int)size[0]];
clGetDeviceInfo(device, paramName,
buffer.length, Pointer.to(buffer), null);
return new String(buffer, 0, buffer.length-1);
}
private static String getString(cl_platform_id platform, int paramName)
{
long size[] = new long[1];
clGetPlatformInfo(platform, paramName, 0, null, size);
byte buffer[] = new byte[(int)size[0]];
clGetPlatformInfo(platform, paramName,
buffer.length, Pointer.to(buffer), null);
return new String(buffer, 0, buffer.length-1);
}
}
Output for me:
Platform: AMD Accelerated Parallel Processing
CL version: 2.0
Device: Spectre
SVM capabilities: CL_DEVICE_SVM_COARSE_GRAIN_BUFFER
Device: AMD A10-7850K Radeon R7, 12 Compute Cores 4C+8G
SVM capabilities: CL_DEVICE_SVM_COARSE_GRAIN_BUFFER CL_DEVICE_SVM_FINE_GRAIN_BUFFER CL_DEVICE_SVM_FINE_GRAIN_SYSTEM CL_DEVICE_SVM_ATOMICS
Platform: NVIDIA CUDA
CL version: 1.2
(no SVM support)
