Replace faiss bfKnn (#1202)

Replace faiss bfKnn with code that leverages our pairwise_distance api and select_k api - by tiling over the inputs.

This lets us remove faiss as a dependency

Closes #798 
Closes #1159

Authors:
  - Ben Frederickson (https://github.com/benfred)
  - Corey J. Nolet (https://github.com/cjnolet)

Approvers:
  - Corey J. Nolet (https://github.com/cjnolet)
  - Ray Douglass (https://github.com/raydouglass)

URL: #1202

ci/checks/copyright.py

@@ -37,7 +37,7 @@
     re.compile(r"setup[.]cfg$"),
     re.compile(r"meta[.]yaml$")
 ]
-ExemptFiles = ["cpp/include/raft/spatial/knn/detail/faiss_select/"]
+ExemptFiles = ["cpp/include/raft/neighbors/detail/faiss_select/"]
 
 # this will break starting at year 10000, which is probably OK :)
 CheckSimple = re.compile(

cpp/include/raft/core/resource/cublas_handle.hpp

@@ -71,7 +71,9 @@ inline cublasHandle_t get_cublas_handle(resources const& res)
     cudaStream_t stream = get_cuda_stream(res);
     res.add_resource_factory(std::make_shared<cublas_resource_factory>(stream));
   }
-  return *res.get_resource<cublasHandle_t>(resource_type::CUBLAS_HANDLE);
+  auto ret = *res.get_resource<cublasHandle_t>(resource_type::CUBLAS_HANDLE);
+  RAFT_CUBLAS_TRY(cublasSetStream(ret, get_cuda_stream(res)));
+  return ret;
 };
 
 /**

cpp/include/raft/distance/distance_types.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021-2022, NVIDIA CORPORATION.
+ * Copyright (c) 2021-2023, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -66,6 +66,26 @@ enum DistanceType : unsigned short {
   Precomputed = 100
 };
 
+/**
+ * Whether minimal distance corresponds to similar elements (using the given metric).
+ */
+inline bool is_min_close(DistanceType metric)
+{
+  bool select_min;
+  switch (metric) {
+    case DistanceType::InnerProduct:
+    case DistanceType::CosineExpanded:
+    case DistanceType::CorrelationExpanded:
+      // Similarity metrics have the opposite meaning, i.e. nearest neighbors are those with larger
+      // similarity (See the same logic at cpp/include/raft/sparse/spatial/detail/knn.cuh:362
+      // {perform_k_selection})
+      select_min = false;
+      break;
+    default: select_min = true;
+  }
+  return select_min;
+}
+
 namespace kernels {
 enum KernelType { LINEAR, POLYNOMIAL, RBF, TANH };
 

cpp/include/raft/linalg/detail/transpose.cuh

@@ -37,6 +37,7 @@ void transpose(raft::device_resources const& handle,
                cudaStream_t stream)
 {
   cublasHandle_t cublas_h = handle.get_cublas_handle();
+  RAFT_CUBLAS_TRY(cublasSetStream(cublas_h, stream));
 
   int out_n_rows = n_cols;
   int out_n_cols = n_rows;
@@ -90,6 +91,7 @@ void transpose_row_major_impl(
   auto out_n_cols   = in.extent(0);
   T constexpr kOne  = 1;
   T constexpr kZero = 0;
+
   CUBLAS_TRY(cublasgeam(handle.get_cublas_handle(),
                         CUBLAS_OP_T,
                         CUBLAS_OP_N,
@@ -116,6 +118,7 @@ void transpose_col_major_impl(
   auto out_n_cols   = in.extent(0);
   T constexpr kOne  = 1;
   T constexpr kZero = 0;
+
   CUBLAS_TRY(cublasgeam(handle.get_cublas_handle(),
                         CUBLAS_OP_T,
                         CUBLAS_OP_N,

cpp/include/raft/neighbors/brute_force.cuh

@@ -18,9 +18,8 @@
 
 #include <raft/core/device_mdspan.hpp>
 #include <raft/distance/distance_types.hpp>
+#include <raft/neighbors/detail/knn_brute_force.cuh>
 #include <raft/spatial/knn/detail/fused_l2_knn.cuh>
-#include <raft/spatial/knn/detail/knn_brute_force_faiss.cuh>
-#include <raft/spatial/knn/detail/selection_faiss.cuh>
 
 namespace raft::neighbors::brute_force {
 
@@ -96,15 +95,15 @@ inline void knn_merge_parts(
                "Number of columns in output indices and distances matrices must be equal to k");
 
   auto n_parts = in_keys.extent(0) / n_samples;
-  spatial::knn::detail::knn_merge_parts(in_keys.data_handle(),
-                                        in_values.data_handle(),
-                                        out_keys.data_handle(),
-                                        out_values.data_handle(),
-                                        n_samples,
-                                        n_parts,
-                                        in_keys.extent(1),
-                                        handle.get_stream(),
-                                        translations.value_or(nullptr));
+  detail::knn_merge_parts(in_keys.data_handle(),
+                          in_values.data_handle(),
+                          out_keys.data_handle(),
+                          out_values.data_handle(),
+                          n_samples,
+                          n_parts,
+                          in_keys.extent(1),
+                          handle.get_stream(),
+                          translations.value_or(nullptr));
 }
 
 /**
@@ -181,21 +180,21 @@ void knn(raft::device_resources const& handle,
 
   std::vector<idx_t>* trans_arg = global_id_offset.has_value() ? &trans : nullptr;
 
-  raft::spatial::knn::detail::brute_force_knn_impl(handle,
-                                                   inputs,
-                                                   sizes,
-                                                   static_cast<value_int>(index[0].extent(1)),
-                                                   // TODO: This is unfortunate. Need to fix.
-                                                   const_cast<value_t*>(search.data_handle()),
-                                                   static_cast<value_int>(search.extent(0)),
-                                                   indices.data_handle(),
-                                                   distances.data_handle(),
-                                                   k,
-                                                   rowMajorIndex,
-                                                   rowMajorQuery,
-                                                   trans_arg,
-                                                   metric,
-                                                   metric_arg.value_or(2.0f));
+  raft::neighbors::detail::brute_force_knn_impl(handle,
+                                                inputs,
+                                                sizes,
+                                                static_cast<value_int>(index[0].extent(1)),
+                                                // TODO: This is unfortunate. Need to fix.
+                                                const_cast<value_t*>(search.data_handle()),
+                                                static_cast<value_int>(search.extent(0)),
+                                                indices.data_handle(),
+                                                distances.data_handle(),
+                                                k,
+                                                rowMajorIndex,
+                                                rowMajorQuery,
+                                                trans_arg,
+                                                metric,
+                                                metric_arg.value_or(2.0f));
 }
 
 /**

cpp/include/raft/spatial/knn/detail/faiss_select/Comparators.cuh → cpp/include/raft/neighbors/detail/faiss_select/Comparators.cuh

@@ -10,7 +10,7 @@
 #include <cuda.h>
 #include <cuda_fp16.h>
 
-namespace raft::spatial::knn::detail::faiss_select {
+namespace raft::neighbors::detail::faiss_select {
 
 template <typename T>
 struct Comparator {
@@ -26,4 +26,4 @@ struct Comparator<half> {
   __device__ static inline bool gt(half a, half b) { return __hgt(a, b); }
 };
 
-}  // namespace raft::spatial::knn::detail::faiss_select
+}  // namespace raft::neighbors::detail::faiss_select

cpp/include/raft/neighbors/detail/faiss_select/DistanceUtils.h

@@ -0,0 +1,52 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file thirdparty/LICENSES/LICENSE.faiss
+ */
+
+#pragma once
+
+namespace raft::neighbors::detail::faiss_select {
+// If the inner size (dim) of the vectors is small, we want a larger query tile
+// size, like 1024
+inline void chooseTileSize(size_t numQueries,
+                           size_t numCentroids,
+                           size_t dim,
+                           size_t elementSize,
+                           size_t totalMem,
+                           size_t& tileRows,
+                           size_t& tileCols)
+{
+  // The matrix multiplication should be large enough to be efficient, but if
+  // it is too large, we seem to lose efficiency as opposed to
+  // double-streaming. Each tile size here defines 1/2 of the memory use due
+  // to double streaming. We ignore available temporary memory, as that is
+  // adjusted independently by the user and can thus meet these requirements
+  // (or not). For <= 4 GB GPUs, prefer 512 MB of usage. For <= 8 GB GPUs,
+  // prefer 768 MB of usage. Otherwise, prefer 1 GB of usage.
+  size_t targetUsage = 0;
+
+  if (totalMem <= ((size_t)4) * 1024 * 1024 * 1024) {
+    targetUsage = 512 * 1024 * 1024;
+  } else if (totalMem <= ((size_t)8) * 1024 * 1024 * 1024) {
+    targetUsage = 768 * 1024 * 1024;
+  } else {
+    targetUsage = 1024 * 1024 * 1024;
+  }
+
+  targetUsage /= 2 * elementSize;
+
+  // 512 seems to be a batch size sweetspot for float32.
+  // If we are on float16, increase to 512.
+  // If the k size (vec dim) of the matrix multiplication is small (<= 32),
+  // increase to 1024.
+  size_t preferredTileRows = 512;
+  if (dim <= 32) { preferredTileRows = 1024; }
+
+  tileRows = std::min(preferredTileRows, numQueries);
+
+  // tileCols is the remainder size
+  tileCols = std::min(targetUsage / preferredTileRows, numCentroids);
+}
+}  // namespace raft::neighbors::detail::faiss_select

cpp/include/raft/spatial/knn/detail/faiss_select/MergeNetworkBlock.cuh → cpp/include/raft/neighbors/detail/faiss_select/MergeNetworkBlock.cuh

@@ -8,10 +8,10 @@
 #pragma once
 
 #include <cuda.h>
-#include <raft/spatial/knn/detail/faiss_select/MergeNetworkUtils.cuh>
-#include <raft/spatial/knn/detail/faiss_select/StaticUtils.h>
+#include <raft/neighbors/detail/faiss_select/MergeNetworkUtils.cuh>
+#include <raft/neighbors/detail/faiss_select/StaticUtils.h>
 
-namespace raft::spatial::knn::detail::faiss_select {
+namespace raft::neighbors::detail::faiss_select {
 
 // Merge pairs of lists smaller than blockDim.x (NumThreads)
 template <int NumThreads,
@@ -274,4 +274,4 @@ inline __device__ void blockMerge(K* listK, V* listV)
   BlockMerge<NumThreads, K, V, N, L, Dir, Comp, kSmallerThanBlock, FullMerge>::merge(listK, listV);
 }
 
-}  // namespace raft::spatial::knn::detail::faiss_select
+}  // namespace raft::neighbors::detail::faiss_select

cpp/include/raft/spatial/knn/detail/faiss_select/MergeNetworkUtils.cuh → cpp/include/raft/neighbors/detail/faiss_select/MergeNetworkUtils.cuh

@@ -7,7 +7,7 @@
 
 #pragma once
 
-namespace raft::spatial::knn::detail::faiss_select {
+namespace raft::neighbors::detail::faiss_select {
 
 template <typename T>
 inline __device__ void swap(bool swap, T& x, T& y)
@@ -22,4 +22,4 @@ inline __device__ void assign(bool assign, T& x, T y)
 {
   x = assign ? y : x;
 }
-}  // namespace raft::spatial::knn::detail::faiss_select
+}  // namespace raft::neighbors::detail::faiss_select

cpp/include/raft/spatial/knn/detail/faiss_select/MergeNetworkWarp.cuh → cpp/include/raft/neighbors/detail/faiss_select/MergeNetworkWarp.cuh

@@ -7,12 +7,12 @@
 
 #pragma once
 
-#include <raft/spatial/knn/detail/faiss_select/MergeNetworkUtils.cuh>
-#include <raft/spatial/knn/detail/faiss_select/StaticUtils.h>
+#include <raft/neighbors/detail/faiss_select/MergeNetworkUtils.cuh>
+#include <raft/neighbors/detail/faiss_select/StaticUtils.h>
 
 #include <raft/util/cuda_utils.cuh>
 
-namespace raft::spatial::knn::detail::faiss_select {
+namespace raft::neighbors::detail::faiss_select {
 
 //
 // This file contains functions to:
@@ -518,4 +518,4 @@ inline __device__ void warpSortAnyRegisters(K k[N], V v[N])
   BitonicSortStep<K, V, N, Dir, Comp>::sort(k, v);
 }
 
-}  // namespace raft::spatial::knn::detail::faiss_select
+}  // namespace raft::neighbors::detail::faiss_select

cpp/include/raft/spatial/knn/detail/faiss_select/Select.cuh → cpp/include/raft/neighbors/detail/faiss_select/Select.cuh

@@ -7,14 +7,14 @@
 
 #pragma once
 
-#include <raft/spatial/knn/detail/faiss_select/Comparators.cuh>
-#include <raft/spatial/knn/detail/faiss_select/MergeNetworkBlock.cuh>
-#include <raft/spatial/knn/detail/faiss_select/MergeNetworkWarp.cuh>
+#include <raft/neighbors/detail/faiss_select/Comparators.cuh>
+#include <raft/neighbors/detail/faiss_select/MergeNetworkBlock.cuh>
+#include <raft/neighbors/detail/faiss_select/MergeNetworkWarp.cuh>
 
 #include <raft/core/kvp.hpp>
 #include <raft/util/cuda_utils.cuh>
 
-namespace raft::spatial::knn::detail::faiss_select {
+namespace raft::neighbors::detail::faiss_select {
 
 // Specialization for block-wide monotonic merges producing a merge sort
 // since what we really want is a constexpr loop expansion
@@ -552,4 +552,4 @@ struct WarpSelect<K, V, Dir, Comp, 1, NumThreadQ, ThreadsPerBlock> {
   V threadV;
 };
 
-}  // namespace raft::spatial::knn::detail::faiss_select
+}  // namespace raft::neighbors::detail::faiss_select

cpp/include/raft/spatial/knn/detail/faiss_select/StaticUtils.h → cpp/include/raft/neighbors/detail/faiss_select/StaticUtils.h

@@ -15,7 +15,7 @@
 #define __device__
 #endif
 
-namespace raft::spatial::knn::detail::faiss_select::utils {
+namespace raft::neighbors::detail::faiss_select::utils {
 
 template <typename T>
 constexpr __host__ __device__ bool isPowerOf2(T v)
@@ -45,4 +45,4 @@ static_assert(nextHighestPowerOf2(1536000000u) == 2147483648u, "nextHighestPower
 static_assert(nextHighestPowerOf2((size_t)2147483648ULL) == (size_t)4294967296ULL,
               "nextHighestPowerOf2");
 
-}  // namespace raft::spatial::knn::detail::faiss_select::utils
+}  // namespace raft::neighbors::detail::faiss_select::utils

cpp/include/raft/spatial/knn/detail/faiss_select/key_value_block_select.cuh → cpp/include/raft/neighbors/detail/faiss_select/key_value_block_select.cuh

@@ -7,14 +7,14 @@
 
 #pragma once
 
-#include <raft/spatial/knn/detail/faiss_select/MergeNetworkUtils.cuh>
-#include <raft/spatial/knn/detail/faiss_select/Select.cuh>
+#include <raft/neighbors/detail/faiss_select/MergeNetworkUtils.cuh>
+#include <raft/neighbors/detail/faiss_select/Select.cuh>
 
 // TODO: Need to think further about the impact (and new boundaries created) on the registers
 // because this will change the max k that can be processed. One solution might be to break
 // up k into multiple batches for larger k.
 
-namespace raft::spatial::knn::detail::faiss_select {
+namespace raft::neighbors::detail::faiss_select {
 
 // `Dir` true, produce largest values.
 // `Dir` false, produce smallest values.
@@ -221,4 +221,4 @@ struct KeyValueBlockSelect {
   int kMinus1;
 };
 
-}  // namespace raft::spatial::knn::detail::faiss_select
+}  // namespace raft::neighbors::detail::faiss_select

cpp/include/raft/neighbors/detail/ivf_flat_search.cuh

@@ -1244,26 +1244,6 @@ void search_impl(raft::device_resources const& handle,
   }
 }
 
-/**
- * Whether minimal distance corresponds to similar elements (using the given metric).
- */
-inline bool is_min_close(distance::DistanceType metric)
-{
-  bool select_min;
-  switch (metric) {
-    case raft::distance::DistanceType::InnerProduct:
-    case raft::distance::DistanceType::CosineExpanded:
-    case raft::distance::DistanceType::CorrelationExpanded:
-      // Similarity metrics have the opposite meaning, i.e. nearest neighbors are those with larger
-      // similarity (See the same logic at cpp/include/raft/sparse/spatial/detail/knn.cuh:362
-      // {perform_k_selection})
-      select_min = false;
-      break;
-    default: select_min = true;
-  }
-  return select_min;
-}
-
 /** See raft::neighbors::ivf_flat::search docs */
 template <typename T, typename IdxT>
 inline void search(raft::device_resources const& handle,
@@ -1295,7 +1275,7 @@ inline void search(raft::device_resources const& handle,
                                      n_queries,
                                      k,
                                      n_probes,
-                                     is_min_close(index.metric()),
+                                     raft::distance::is_min_close(index.metric()),
                                      neighbors,
                                      distances,
                                      mr);