Pointer from Different Device

Occurs when memory is allocated on a device using a pointer from another device.

Problem type: Memory leak

ID	Code Location	Description
1	Allocation site	Represents source location of memory allocation on device. If a pointer allocated for a certain device is used for memory allocation on a different device, the pointer is considered invalid.

DPC++ Example

cl::sycl::queue queue_1(cl::sycl::cpu_selector{}); 

cl::sycl::queue queue_2(cl::sycl::cpu_selector{}); 

int* deviceData  = (int*)sycl::malloc_device(sizeInBytes, queue_1.get_device(), queue_1.get_context()); 

queue_2.submit([&](cl::sycl::handler &cgh) 

{ 

    cgh.parallel_for<class kernel1>(range, 

                                    [=](cl::sycl::item<1> itemID) 

                                    { 

                                        size_t i = itemID.get_id(0); 

                                        deviceData[i] = i + 1;   

                                    }); 

}

Possible Correction Strategies

To avoid the problem, use the following hints:

Check if the pointer you are using matches the device it was allocated for.
Consider converting device pointers into shared memory pointers applicable to multiple device types.