5 Commits

Author SHA1 Message Date
Georgia Gkioxari
b2b0c5a442 knn autograd
Summary:
Adds knn backward to return `grad_pts1` and `grad_pts2`. Adds `knn_gather` to return the nearest neighbors in pts2.

The BM tests include backward pass and are ran on an M40.
```
Benchmark                               Avg Time(μs)      Peak Time(μs) Iterations
--------------------------------------------------------------------------------
KNN_SQUARE_32_256_128_3_24_cpu              39558           43485             13
KNN_SQUARE_32_256_128_3_24_cuda:0            1080            1404            463
KNN_SQUARE_32_256_512_3_24_cpu              81950           85781              7
KNN_SQUARE_32_256_512_3_24_cuda:0            1519            1641            330
--------------------------------------------------------------------------------

Benchmark                               Avg Time(μs)      Peak Time(μs) Iterations
--------------------------------------------------------------------------------
KNN_RAGGED_32_256_128_3_24_cpu              13798           14650             37
KNN_RAGGED_32_256_128_3_24_cuda:0            1576            1713            318
KNN_RAGGED_32_256_512_3_24_cpu              31255           32210             16
KNN_RAGGED_32_256_512_3_24_cuda:0            2024            2162            248
--------------------------------------------------------------------------------
```

Reviewed By: jcjohnson

Differential Revision: D20945556

fbshipit-source-id: a16f616029c6b5f8c2afceb5f2bc12c5c20d2f3c
2020-04-14 17:22:56 -07:00
Jeremy Reizenstein
01b5f7b228 heterogenous KNN
Summary: Interface and working implementation of ragged KNN. Benchmarks (which aren't ragged) haven't slowed. New benchmark shows that ragged is faster than non-ragged of the same shape.

Reviewed By: jcjohnson

Differential Revision: D20696507

fbshipit-source-id: 21b80f71343a3475c8d3ee0ce2680f92f0fae4de
2020-04-07 01:47:37 -07:00
Patrick Labatut
d57daa6f85 Address black + isort fbsource linter warnings
Summary: Address black + isort fbsource linter warnings from D20558374 (previous diff)

Reviewed By: nikhilaravi

Differential Revision: D20558373

fbshipit-source-id: d3607de4a01fb24c0d5269634563a7914bddf1c8
2020-03-29 14:51:02 -07:00
Jeremy Reizenstein
37c5c8e0b6 Linter, deprecated type()
Summary: Run linter after recent changes. Fix long comment in knn.h which clang-format has reflowed badly. Add crude test that code doesn't call deprecated `.type()` or `.data()`.

Reviewed By: nikhilaravi

Differential Revision: D20692935

fbshipit-source-id: 28ce0308adae79a870cb41a810b7cf8744f41ab8
2020-03-29 14:02:58 -07:00
Justin Johnson
870290df34 Implement K-Nearest Neighbors
Summary:
Implements K-Nearest Neighbors with C++ and CUDA versions.

KNN in CUDA is highly nontrivial. I've implemented a few different versions of the kernel, and we heuristically dispatch to different kernels based on the problem size. Some of the kernels rely on template specialization on either D or K, so we use template metaprogramming to compile specialized versions for ranges of D and K.

These kernels are up to 3x faster than our existing 1-nearest-neighbor kernels, so we should also consider swapping out `nn_points_idx` to use these kernels in the backend.

I've been working mostly on the CUDA kernels, and haven't converged on the correct Python API.

I still want to benchmark against FAISS to see how far away we are from their performance.

Reviewed By: bottler

Differential Revision: D19729286

fbshipit-source-id: 608ffbb7030c21fe4008f330522f4890f0c3c21a
2020-03-26 13:40:26 -07:00