# Help Debugging GPU Performance Issue

**URL:** https://discourse.julialang.org/t/help-debugging-gpu-performance-issue/42274
**Category:** GPU
**Tags:** gpu, debug, cuarrays
**Created:** [June 29, 2020, 9:46pm UTC](https://discourse.julialang.org/t/help-debugging-gpu-performance-issue/42274 "2020-06-29T21:46:02Z")
**Posts on this page:** 1
**Showing post:** 3

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### Author: ![maleadt](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/maleadt/32/10097_2.png) [@maleadt](https://discourse.julialang.org/u/maleadt)
#### Post date: [July 1, 2020, 8:15am UTC](https://discourse.julialang.org/t/help-debugging-gpu-performance-issue/42274/3 "2020-07-01T08:15:27Z")

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> [@Ellipse0934](#):
>
> Now the only thing that pops out to my eyes is the allocations which can be explained by the `unsafe_free!` .

The allocations reported by BenchmarkTools are CPU allocations, and there are always some when launching kernels (we need to allocate kernel parameter buffers to pass to CUDA). To see GPU allocations, you can use `CUDA.@time`.

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