Possible memory leak when collecting events for profiling about pyopencl

[inducer]

Can something like valgrind maybe provide details on where those allocations are taking place?

[kif]

Here are the valgrind "massif" profile for two calls of the program when running on a limited number of images (2000), with and without profiling activated. Valgrind still suggests to look at h5py rather than pyopencl but the triggering of the option makes 16G difference in memory consumption.

Without profiling:

With profiling:

[kif]

I run it several other times and it looks like the profiling in OpenCL prevents the memory from being freed.

[kif]

So I tired to collect only timestamps for each event instead of the complete process.
The patch is for now implemented in:
silx-kit/silx#3690

The memory profile looks like this, now. One would have expected 10 memory free (since 10 files are processed) but fewer are visible.

[kif]

I got struck by something similar in another project ... but profiling was not involved this time.
https://github.com/kif/multianalyzer/blob/main/multianalyzer/opencl.py
The pattern was similar: read data from an HDF5 file with large chunks and send them to the GPU ...
But once again, unable to reproduce the behaviour within a self contained script.
Calling the pyopencl.array method finalize helps in freeing the memory on the CPU