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ENH: kernels for random.vonmisses; part 2 #681

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@samir-nasibli samir-nasibli commented Apr 14, 2021

Description

Enable computations on devices [CPU/GPU].

Tests

  • DPNP own:
tests/test_random.py::TestDistributionsVonmises::test_moments[large_kappa] PASSED
tests/test_random.py::TestDistributionsVonmises::test_moments[small_kappa] PASSED
tests/test_random.py::TestDistributionsVonmises::test_invalid_args PASSED
tests/test_random.py::TestDistributionsVonmises::test_seed[large_kappa] FAILED
tests/test_random.py::TestDistributionsVonmises::test_seed[small_kappa] FAILED
  • + numpy external

TODO

tests/test_random.py::TestDistributionsVonmises::test_seed failed on both devices. Bug.

@samir-nasibli samir-nasibli added the in progress Please do not merge. Work is in progress. label Apr 14, 2021
@samir-nasibli samir-nasibli removed the in progress Please do not merge. Work is in progress. label Apr 14, 2021
@samir-nasibli samir-nasibli added the in progress Please do not merge. Work is in progress. label Apr 17, 2021
@@ -1242,65 +1243,70 @@ void dpnp_rng_vonmises_large_kappa_c(void* result, const _DataType mu, const _Da

Uvec = reinterpret_cast<_DataType*>(dpnp_memory_alloc_c(size * sizeof(_DataType)));
Vvec = reinterpret_cast<_DataType*>(dpnp_memory_alloc_c(size * sizeof(_DataType)));

for (size_t n = 0; n < size;)
n = reinterpret_cast<size_t*>(dpnp_memory_alloc_c(sizeof(size_t)));
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this is quite strange (Make scalar as a array with one element).
I think it should be a scalar, not an array.

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scalar and this is the same. You just can not pass n to sycl region in other way.

Y = 0.0;
else if (Y > 1.0)
Y = 1.0;
n[0] = n[0] + 1;
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This is a mistake. This is parallel environment (SYCL kernel). Writing inside the kernel into same memory cause https://en.wikipedia.org/wiki/Race_condition

V = Vvec[i];
sn2 = sn * sn;
cn2 = cn * cn;
auto paral_kernel_some = [&](cl::sycl::handler& cgh) {
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@shssf shssf May 13, 2021

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Kernel inside the loop with bigger trip count. It would be more efficient to parallelize (make kernel) the algorithm by bigger value size instead size-n. So, it will require a loop inside the kernel.
It is questionable what will be more performant

  1. loop with a kernels queue (data dependent)
  2. kernel with a loop

It is hard to predict it with no perf measurements but I would vote that parallelization with bigger number of threads should be better.

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shssf commented Jun 22, 2021

@samir-nasibli Is this PR ready to review or still in development stage?

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@samir-nasibli Is this PR ready to review or still in development stage?

I will update this PR or move some part of this changes to another PR with closing this.

@samir-nasibli samir-nasibli changed the title ENH: kernels for random.vonmisses ENH: kernels for random.vonmisses; part 2 Jul 12, 2021
Comment on lines 1314 to 1315
*n = *n + 1;
result1[*n] = cl::sycl::asin(cl::sycl::sqrt(Y));
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Looks like here we are getting race condition, that is why we are getting wrong results. To prevent it we should calculate n (index of result) from i.

Comment on lines 1400 to 1401
*n = *n + 1;
result1[*n] = cl::sycl::acos(W);
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Looks like here we are getting race condition, that is why we are getting wrong results. To prevent it we should calculate n (index of result) from i.

* Fix race condition in dpnp_rng_vonmises_small_kappa_c and dpnp_rng_vonmises_large_kappa_c

* Rename arrays and change if condition from kernels in dpnp_rng_vonmises_large_kappa_c and dpnp_rng_vonmises_small_kappa_c

* Add space

* Fix indices in dpnp_rng_vonmises_small_kappa_c and dpnp_rng_vonmises_large_kappa_c
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samir-nasibli commented Oct 7, 2021

@LukichevaPolina
The use of extra memory with the amount of data is not a good practice in optimization. We must avoid this cases.
We have to remove the possibilities for a potential race condition in the algorithm.

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densmirn commented Oct 7, 2021

The use of extra memory with the amount of data is not a good practice in optimization. We must avoid this cases. - ideas?
We have to remove the possibilities for a potential race condition in the algorithm. - done

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The use of extra memory with the amount of data is not a good practice in optimization. We must avoid this cases. - ideas?
We have to remove the possibilities for a potential race condition in the algorithm. - done

  1. Any optimization with the use of additional memory can actually degrade (depending on the input data) and underestimate all the benefits from parallelism. Allocation/Deallocation/Working with additional memory is expensive.

  2. We have to remove the possibilities for a potential race condition in the algorithm. - done

using extra mem is brute force approach.

  1. - ideas?

We need to investigate it.

  1. I also recommend to use perf tests and profiler tools during optimization. Comparative analysis is important in such work.

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Stale PR?

@antonwolfy antonwolfy marked this pull request as draft February 20, 2024 17:03
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6 participants