From e84250e8b49267e092f58ebe66a9373a9c940122 Mon Sep 17 00:00:00 2001
From: Yuang Liu <liuyuang@baidu.com>
Date: Tue, 9 Aug 2022 10:30:49 +0800
Subject: [PATCH] [model parallel] enable mp to use fused linear (#44968)

---
 .../parallel_layers/mp_layers.py              | 58 +++++++++++++++----
 1 file changed, 48 insertions(+), 10 deletions(-)

diff --git a/python/paddle/distributed/fleet/meta_parallel/parallel_layers/mp_layers.py b/python/paddle/distributed/fleet/meta_parallel/parallel_layers/mp_layers.py
index 14ca1322e78..c9d7c71dbbb 100644
--- a/python/paddle/distributed/fleet/meta_parallel/parallel_layers/mp_layers.py
+++ b/python/paddle/distributed/fleet/meta_parallel/parallel_layers/mp_layers.py
@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import paddle
+from paddle.fluid import core
 from paddle.fluid.dygraph.layers import Layer
 from .random import get_rng_state_tracker
 from paddle.nn import functional as F
@@ -27,6 +28,13 @@ __all__ = []
 # language models using model parallelism[J]. arXiv preprint arXiv:1909.08053, 2019. (https://arxiv.org/abs/1909.08053)
 
 
+def is_fused_matmul_bias_supported():
+    if paddle.is_compiled_with_cuda() and not paddle.is_compiled_with_rocm():
+        return hasattr(core.ops, 'fused_gemm_epilogue')
+    else:
+        return False
+
+
 class VocabParallelEmbedding(Layer):
 
     def __init__(self,
@@ -100,7 +108,8 @@ class ColumnParallelLinear(Layer):
                  weight_attr=None,
                  has_bias=None,
                  gather_output=True,
-                 name=None):
+                 name=None,
+                 fuse_matmul_bias=False):
         super(ColumnParallelLinear, self).__init__()
 
         self.model_parallel_group = tp._HYBRID_PARALLEL_GROUP.get_model_parallel_group(
@@ -147,6 +156,18 @@ class ColumnParallelLinear(Layer):
         else:
             self.bias = None
 
+        self.linear = F.linear
+
+        if fuse_matmul_bias:
+            if not is_fused_matmul_bias_supported():
+                raise NotImplementedError(
+                    "You set fuse_matmul_bias=True in ColumnParallelLinear, "
+                    "however, the paddle you are using not support this operation. "
+                    "Please set fuse_matmul_bias=False or use paddle compiled "
+                    "with cuda 11.6 or higher.")
+            from paddle.incubate.nn.functional import fused_linear
+            self.linear = fused_linear
+
     def forward(self, x):
         # use inner api to process identity
         if self.is_mp:
@@ -155,10 +176,10 @@ class ColumnParallelLinear(Layer):
         else:
             input_parallel = x
 
-        output_parallel = F.linear(input_parallel,
-                                   self.weight,
-                                   self.bias,
-                                   name=self._name)
+        output_parallel = self.linear(input_parallel,
+                                      self.weight,
+                                      self.bias,
+                                      name=self._name)
 
         if self.gather_output and self.is_mp:
             output = paddle.distributed.collective._c_concat(
@@ -176,7 +197,8 @@ class RowParallelLinear(Layer):
                  weight_attr=None,
                  has_bias=True,
                  input_is_parallel=False,
-                 name=None):
+                 name=None,
+                 fuse_matmul_bias=False):
         super(RowParallelLinear, self).__init__()
 
         self.in_features = in_features
@@ -225,6 +247,18 @@ class RowParallelLinear(Layer):
         else:
             self.bias = None
 
+        self.linear = F.linear
+
+        if fuse_matmul_bias:
+            if not is_fused_matmul_bias_supported():
+                raise NotImplementedError(
+                    "You set fuse_matmul_bias=True in RowParallelLinear, "
+                    "however, the paddle you are using not support this operation. "
+                    "Please set fuse_matmul_bias=False or use paddle compiled "
+                    "with cuda 11.6 or higher.")
+            from paddle.incubate.nn.functional import fused_linear
+            self.linear = fused_linear
+
     def forward(self, x):
         if self.input_is_parallel or (not self.is_mp):
             input_parallel = x
@@ -233,18 +267,22 @@ class RowParallelLinear(Layer):
             input_parallel = paddle.distributed.collective._c_split(
                 x, group=self.model_parallel_group)
 
-        output_parallel = F.linear(input_parallel, self.weight, name=self._name)
-
         if self.is_mp:
+            output_parallel = self.linear(input_parallel,
+                                          self.weight,
+                                          name=self._name)
             output_ = paddle.distributed.collective._mp_allreduce(
                 output_parallel,
                 group=self.model_parallel_group,
                 use_calc_stream=True,
                 use_model_parallel=True)
+            output = output_ + self.bias if self.bias is not None else output_
         else:
-            output_ = output_parallel
+            output = self.linear(input_parallel,
+                                 self.weight,
+                                 self.bias,
+                                 name=self._name)
 
-        output = output_ + self.bias if self.bias is not None else output_
         return output
 
 
-- 
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