combine cat + reorder for combined indice into one pass (#1932)

Summary:
Pull Request resolved: #1932

as title. combine cat + reorder into one pass for combined indice to avoid unncessary copy of cat_indices.

Also added a micro benchmark for such case

Differential Revision: D48058732

fbshipit-source-id: 1523f7862bd8bebae41b1dec8a3cee696cfd4aac

fbgemm_gpu/bench/sparse_ops_benchmark.py

@@ -679,5 +679,193 @@ def batch_group_index_select_bwd(
     )
 
 
+@cli.command()
+@click.option("--batch-size", default=8192)
+@click.option("--table-size", default=20)
+@click.option("--length", default=50)
+@click.option("--num-ads", default=100)
+@click.option("--dtype", type=click.Choice(["float", "long"]), default="long")
+@click.option("--itype", type=click.Choice(["int", "long"]), default="int")
+@click.option("--broadcast-indices", type=bool, default=True)
+def cat_reorder_batched_ad_indices_bench(
+    batch_size: int,
+    table_size: int,
+    length: int,
+    num_ads: int,
+    dtype: str,
+    itype: str,
+    broadcast_indices: bool,
+) -> None:
+    assert dtype == "float" or dtype == "long", "Only int and long are supported"
+    data_type = torch.int64 if dtype == "long" else torch.float
+    data_size = 8 if dtype == "long" else 4
+
+    assert itype == "int" or itype == "long", "Only int and long are supported"
+
+    if broadcast_indices:
+        ad_indices = [
+            (
+                torch.randint(
+                    low=0,
+                    high=100,
+                    size=(table_size * length,),
+                )
+                .int()
+                .to(data_type)
+            )
+            for _ in range(batch_size)
+        ]
+        ad_lengths = [
+            torch.tensor([length for _ in range(table_size)]).int()
+            for _ in range(batch_size)
+        ]
+    else:
+        ad_indices = [
+            (
+                torch.randint(
+                    low=0,
+                    high=100,
+                    size=(table_size * num_ads * length,),
+                )
+                .int()
+                .to(data_type)
+            )
+            for _ in range(batch_size)
+        ]
+        ad_lengths = [
+            torch.tensor([length for _ in range(table_size * num_ads)]).int()
+            for _ in range(batch_size)
+        ]
+
+    batch_offsets = torch.tensor([num_ads * b for b in range(batch_size + 1)]).int()
+    num_ads_in_batch = batch_size * num_ads
+
+    # pyre-ignore
+    def pass_1(ad_indices, ad_lengths, batch_offsets, num_ads_in_batch):
+        cat_ad_lengths = torch.cat(ad_lengths, 0).to("cuda", non_blocking=True)
+        cat_ad_indices = torch.cat(ad_indices, 0).to("cuda", non_blocking=True)
+        batch_offsets = batch_offsets.to("cuda", non_blocking=True)
+        reordered_cat_ad_lengths = torch.ops.fbgemm.reorder_batched_ad_lengths(
+            cat_ad_lengths, batch_offsets, num_ads_in_batch, broadcast_indices
+        )
+        cat_ad_offsets = torch.ops.fbgemm.asynchronous_complete_cumsum(cat_ad_lengths)
+        reordered_cat_ad_offsets = torch.ops.fbgemm.asynchronous_complete_cumsum(
+            reordered_cat_ad_lengths
+        )
+        reordered_cat_ad_indices = torch.ops.fbgemm.reorder_batched_ad_indices(
+            cat_ad_offsets,
+            cat_ad_indices,
+            reordered_cat_ad_offsets,
+            batch_offsets,
+            num_ads_in_batch,
+            broadcast_indices,
+            batch_size * table_size * num_ads * length,
+        )
+
+        return reordered_cat_ad_indices, reordered_cat_ad_lengths
+
+    # process length on device and process indice on device
+    # pyre-ignore
+    def pass_2(ad_indices, ad_lengths, batch_offsets, num_ads_in_batch):
+        cat_ad_lengths = torch.cat(ad_lengths, 0)
+
+        reordered_cat_ad_lengths = torch.ops.fbgemm.reorder_batched_ad_lengths(
+            cat_ad_lengths, batch_offsets, num_ads_in_batch, broadcast_indices
+        )
+        cat_ad_offsets = torch.ops.fbgemm.asynchronous_complete_cumsum(cat_ad_lengths)
+        reordered_cat_ad_offsets = torch.ops.fbgemm.asynchronous_complete_cumsum(
+            reordered_cat_ad_lengths
+        )
+        cat_ad_indices = torch.cat(ad_indices, 0)
+
+        reordered_cat_ad_indices = torch.ops.fbgemm.reorder_batched_ad_indices(
+            cat_ad_offsets.to("cuda", non_blocking=True),
+            cat_ad_indices.to("cuda", non_blocking=True),
+            reordered_cat_ad_offsets.to("cuda", non_blocking=True),
+            batch_offsets.to("cuda", non_blocking=True),
+            num_ads_in_batch,
+            broadcast_indices,
+            batch_size * table_size * num_ads * length,
+        )
+
+        return reordered_cat_ad_indices, reordered_cat_ad_lengths.to(
+            "cuda", non_blocking=True
+        )
+
+    # minimize GPU workload + unfused cat + reorder
+    # pyre-ignore
+    def pass_3(ad_indices, ad_lengths, batch_offsets, num_ads_in_batch):
+        cat_ad_lengths = torch.cat(ad_lengths, 0)
+        reordered_cat_ad_lengths = torch.ops.fbgemm.reorder_batched_ad_lengths(
+            cat_ad_lengths, batch_offsets, num_ads_in_batch, broadcast_indices
+        )
+
+        cat_ad_offsets = torch.ops.fbgemm.asynchronous_complete_cumsum(cat_ad_lengths)
+        reordered_cat_ad_offsets = torch.ops.fbgemm.asynchronous_complete_cumsum(
+            reordered_cat_ad_lengths
+        )
+        cat_ad_indices = torch.cat(ad_indices, 0)
+
+        reordered_cat_ad_indices = torch.ops.fbgemm.reorder_batched_ad_indices(
+            cat_ad_offsets,
+            cat_ad_indices,
+            reordered_cat_ad_offsets,
+            batch_offsets,
+            num_ads_in_batch,
+            broadcast_indices,
+            batch_size * table_size * num_ads * length,
+        )
+
+        return reordered_cat_ad_indices.to(
+            "cuda", non_blocking=True
+        ), reordered_cat_ad_lengths.to("cuda", non_blocking=True)
+
+    # minimize GPU workload + fuse cat + reorder
+    # pyre-ignore
+    def pass_4(ad_indices, ad_lengths, batch_offsets, num_ads_in_batch):
+        cat_ad_lengths = torch.cat(ad_lengths, 0)
+        reordered_cat_ad_lengths = torch.ops.fbgemm.reorder_batched_ad_lengths(
+            cat_ad_lengths, batch_offsets, num_ads_in_batch, broadcast_indices
+        )
+
+        cat_ad_offsets = torch.ops.fbgemm.asynchronous_complete_cumsum(cat_ad_lengths)
+        reordered_cat_ad_offsets = torch.ops.fbgemm.asynchronous_complete_cumsum(
+            reordered_cat_ad_lengths
+        )
+
+        reordered_cat_ad_indices = torch.ops.fbgemm.cat_reorder_batched_ad_indices(
+            cat_ad_offsets,
+            ad_indices,
+            reordered_cat_ad_offsets,
+            batch_offsets,
+            num_ads_in_batch,
+            broadcast_indices,
+            batch_size * table_size * num_ads * length,
+        )
+
+        return reordered_cat_ad_indices.to(
+            "cuda", non_blocking=True
+        ), reordered_cat_ad_lengths.to("cuda", non_blocking=True)
+
+    num_bytes = batch_size * table_size * (num_ads + 1) * length * data_size
+
+    # pyre-ignore
+    def ben(fn, name, ad_indices, ad_lengths, batch_offsets, num_ads_in_batch):
+        time, _ = benchmark_torch_function(
+            fn,
+            (ad_indices, ad_lengths, batch_offsets, num_ads_in_batch),
+            num_warmups=50,
+            iters=500,
+        )
+        logging.info(
+            f"{name} fbgemm_gpu time: {time * 1000:.5f} ms ({num_bytes / time / 1e9:.5f} GB/s)"
+        )
+
+    ben(pass_1, "pass_1", ad_indices, ad_lengths, batch_offsets, num_ads_in_batch)
+    ben(pass_2, "pass_2", ad_indices, ad_lengths, batch_offsets, num_ads_in_batch)
+    ben(pass_3, "pass_3", ad_indices, ad_lengths, batch_offsets, num_ads_in_batch)
+    ben(pass_4, "pass_4", ad_indices, ad_lengths, batch_offsets, num_ads_in_batch)
+
+
 if __name__ == "__main__":
     cli()

fbgemm_gpu/include/fbgemm_gpu/sparse_ops.h

@@ -352,7 +352,16 @@ at::Tensor reorder_batched_ad_indices_cpu(
     const int64_t num_ads_in_batch,
     const bool broadcast_indices = false,
     const int64_t num_indices_after_broadcast = -1);
-
+///@ingroup sparse-data-cpu
+at::Tensor cat_reorder_batched_ad_indices_cpu(
+    const at::Tensor& cat_ad_offsets,
+    const std::vector<at::Tensor>& cat_ad_indices,
+    const at::Tensor& reordered_cat_ad_offsets,
+    const at::Tensor& batch_offsets,
+    const int64_t num_ads_in_batch,
+    const bool broadcast_indices,
+    const int64_t num_indices_after_broadcast,
+    const bool pinned_memory = false);
 at::Tensor recat_embedding_grad_output_cuda(
     at::Tensor grad_output, // [B_local][T_global][D]
     const std::vector<int64_t>& num_features_per_rank);

fbgemm_gpu/src/sparse_ops/sparse_ops_cpu.cpp

@@ -1276,6 +1276,72 @@ void reorder_batched_ad_indices_cpu_(
       });
 }
 
+template <typename index_t, typename scalar_t>
+void cat_reorder_batched_ad_indices_cpu_(
+    const Tensor& cat_ad_offsets,
+    const std::vector<Tensor>& ad_indices,
+    const Tensor& reordered_cat_ad_offsets,
+    const Tensor& batch_offsets,
+    const int64_t num_ads_in_batch,
+    const bool broadcast_indices,
+    Tensor& output) {
+  const int64_t nB = batch_offsets.numel() - 1;
+  const int64_t nT = (reordered_cat_ad_offsets.numel() - 1) / num_ads_in_batch;
+
+  const auto* batch_offsets_data = batch_offsets.data_ptr<int32_t>();
+  const auto* cat_ad_offsets_data = cat_ad_offsets.data_ptr<index_t>();
+  const auto* reordered_cat_ad_offsets_data =
+      reordered_cat_ad_offsets.data_ptr<index_t>();
+  auto* output_data = output.data_ptr<scalar_t>();
+  at::parallel_for(
+      0, nB * nT, FALSE_SHARING_PAD, [&](int64_t tb_begin, int64_t tb_end) {
+        auto b_begin = tb_begin / nT;
+        auto b_end = (tb_end + nT - 1) / nT;
+        for (auto b : c10::irange(b_begin, b_end)) {
+          const auto* ad_indices_data = ad_indices[b].data_ptr<scalar_t>();
+          const auto num_ads_b =
+              batch_offsets_data[b + 1] - batch_offsets_data[b];
+          int64_t t_begin = (b == b_begin) ? tb_begin % nT : 0;
+          int64_t t_end =
+              (b == b_end - 1 && tb_end % nT != 0) ? tb_end % nT : nT;
+          for (auto t : c10::irange(t_begin, t_end)) {
+            const auto output_segment_offset_start =
+                t * num_ads_in_batch + batch_offsets_data[b];
+            const auto output_segment_start =
+                reordered_cat_ad_offsets_data[output_segment_offset_start];
+            const int32_t input_segment_offset_start = broadcast_indices
+                ? nT * b + t
+                : nT * batch_offsets_data[b] + t * num_ads_b;
+            const int32_t input_segment_offset_end = broadcast_indices
+                ? input_segment_offset_start + 1
+                : input_segment_offset_start + num_ads_b;
+            const auto based_segment = broadcast_indices
+                ? cat_ad_offsets_data[nT * b]
+                : cat_ad_offsets_data[nT * batch_offsets_data[b]];
+            const auto input_segment_start =
+                cat_ad_offsets_data[input_segment_offset_start] - based_segment;
+            const auto input_segment_end =
+                cat_ad_offsets_data[input_segment_offset_end] - based_segment;
+            const auto num_elements = input_segment_end - input_segment_start;
+            const auto data_size = num_elements * sizeof(scalar_t);
+            if (broadcast_indices) {
+              for (auto j : c10::irange(num_ads_b)) {
+                std::memcpy(
+                    output_data + output_segment_start + j * num_elements,
+                    ad_indices_data + input_segment_start,
+                    data_size);
+              }
+            } else {
+              std::memcpy(
+                  output_data + output_segment_start,
+                  ad_indices_data + input_segment_start,
+                  data_size);
+            }
+          }
+        }
+      });
+}
+
 Tensor reorder_batched_ad_indices_cpu(
     const Tensor& cat_ad_offsets,
     const Tensor& cat_ad_indices,
@@ -1319,6 +1385,47 @@ Tensor reorder_batched_ad_indices_cpu(
   return reordered_cat_ad_indices;
 }
 
+Tensor cat_reorder_batched_ad_indices_cpu(
+    const Tensor& cat_ad_offsets,
+    const std::vector<Tensor>& ad_indices,
+    const Tensor& reordered_cat_ad_offsets,
+    const Tensor& batch_offsets,
+    const int64_t num_ads_in_batch,
+    const bool broadcast_indices,
+    const int64_t total_num_indices,
+    const bool pinned_memory) {
+  TENSOR_ON_CPU(cat_ad_offsets);
+  for (const auto& t : ad_indices) {
+    TENSOR_ON_CPU(t);
+  }
+  TENSOR_ON_CPU(reordered_cat_ad_offsets);
+  TENSOR_ON_CPU(batch_offsets);
+  TORCH_CHECK_GE(total_num_indices, 0);
+  Tensor reordered_cat_ad_indices = at::empty(
+      {total_num_indices},
+      ad_indices[0].options().pinned_memory(pinned_memory));
+  AT_DISPATCH_INDEX_TYPES(
+      cat_ad_offsets.scalar_type(),
+      "cat_reorder_batched_ad_indices_cpu_kernel_1",
+      [&] {
+        AT_DISPATCH_ALL_TYPES(
+            ad_indices[0].scalar_type(),
+            "cat_reorder_batched_ad_indices_cpu_kernel_2",
+            [&] {
+              cat_reorder_batched_ad_indices_cpu_<index_t, scalar_t>(
+                  cat_ad_offsets,
+                  ad_indices,
+                  reordered_cat_ad_offsets,
+                  batch_offsets,
+                  num_ads_in_batch,
+                  broadcast_indices,
+                  reordered_cat_ad_indices);
+            });
+      });
+
+  return reordered_cat_ad_indices;
+}
+
 Tensor offsets_range_cpu(const Tensor& offsets, int64_t range_size) {
   TENSOR_ON_CPU(offsets);
   TENSOR_NDIM_EQUALS(offsets, 1);
@@ -2125,8 +2232,8 @@ void _permute_lengths_cpu_kernel(
       (num_threads + 1) * FALSE_SHARING_PAD, 0);
 
   // First parallel for: populate permuted_lengths, and compute per-thread
-  // summation of lengths (input_offsets_per_thread_cumsum) and permuted_lengths
-  // (output_offsets_per_thread_cumsum)
+  // summation of lengths (input_offsets_per_thread_cumsum) and
+  // permuted_lengths (output_offsets_per_thread_cumsum)
   at::parallel_for(
       0, T * B, FALSE_SHARING_PAD, [&](int64_t tb_begin, int64_t tb_end) {
         index_t current_input_offset = 0;
@@ -2558,6 +2665,8 @@ TORCH_LIBRARY_FRAGMENT(fbgemm, m) {
       "reorder_batched_ad_lengths(Tensor cat_ad_lengths, Tensor batch_offsets, int num_ads_in_batch, bool broadcast_lengths=False) -> Tensor");
   m.def(
       "reorder_batched_ad_indices(Tensor cat_ad_offsets, Tensor cat_ad_indices, Tensor reordered_cat_ad_offsets, Tensor batch_offsets, int num_ads_in_batch, bool broadcast_indices=False, int num_indices_after_broadcast=-1) -> Tensor");
+  m.def(
+      "cat_reorder_batched_ad_indices(Tensor cat_ad_offsets, Tensor[] cat_ad_indices, Tensor reordered_cat_ad_offsets, Tensor batch_offsets, int num_ads_in_batch, bool broadcast_indices, int total_num_indices, bool pinned_memory=False) -> Tensor");
   m.def("offsets_range(Tensor offsets, int range_size) -> Tensor");
   m.def(
       "batched_unary_embeddings(Tensor weight, Tensor table_offsets, Tensor offsets, Tensor indices) -> Tensor");
@@ -2645,6 +2754,9 @@ TORCH_LIBRARY_IMPL(fbgemm, CPU, m) {
       "reorder_batched_ad_lengths", fbgemm_gpu::reorder_batched_ad_lengths_cpu);
   DISPATCH_TO_CPU(
       "reorder_batched_ad_indices", fbgemm_gpu::reorder_batched_ad_indices_cpu);
+  DISPATCH_TO_CPU(
+      "cat_reorder_batched_ad_indices",
+      fbgemm_gpu::cat_reorder_batched_ad_indices_cpu);
   DISPATCH_TO_CPU("offsets_range", fbgemm_gpu::offsets_range_cpu);
   DISPATCH_TO_CPU(
       "batched_unary_embeddings",