CODEWITHSUNDEEP
opencl
user1873073
user1873073

Reputation: 3670

Is it possible to get device load in OpenCL

I know how to use clGetDeviceInfo to query information about the device but I don't know how to get information about the device at runtime. For example, how much global memory is in use right now? How busy have the processing elements been, on average, in the last n nanoseconds?

Upvotes: 0

Views: 343

Answers (2)

Matthias Holzapfel
Matthias Holzapfel

Reputation: 540

What I did to be able to determine the free memory at runtime is write a wrapper around clDevice (or cl::Device in my case) and pipe all buffer allocations through said wrapper.

At the begin of the program, I query the total device memory (CL_DEVICE__GLOBAL_MEM_SIZE) and when buffers are allocated I store their addresses and sizes in a vector so I can subtract the accumulated size of the currently allocated buffers from the total memory.

With OpenCL, you can assign callback calls to the buffers, which are called when the buffer is destroyed (clSetMemObjectDestructorCallback). So I use those to clean up when the buffer is released. Hint: the cl_mem parameter with which the callback is called is NOT a valid mem object. It may have already been destroyed so you cannot query it for its size (that took me a couple of hours, even though it's clearly stated in the standard ...).

This way, I can always know, how much memory is left on the device.

Upvotes: 0

Ani
Ani

Reputation: 10906

AFAIK, no. OpenCL itself does not have any API to query current status of a device. Those are exposed by the vendor of your particular implementation (like the GPUPerfAPI from AMD or the Graphics Performance analyzer from Intel).

Hope this helps.

Upvotes: 1

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