add num_splist to support deterministic for flash_attn_bwd and FlashA…

…ttnUnpaddedGradKernel (PaddlePaddle#56363)

* add num_splist for flash_attn_bwd and FlashAttnUnpaddedGradKernel

* Add assertTrue

* Update submodule to a specific commit

paddle/phi/kernels/gpu/flash_attn_grad_kernel.cu

@@ -28,6 +28,11 @@ PD_DECLARE_bool(cudnn_deterministic);
 
 namespace phi {
 
+int get_num_split() {
+  // 0 for an internal heuristic, which is optimal
+  return FLAGS_cudnn_deterministic ? 1 : 0;
+}
+
 template <typename T, typename Context>
 void FlashAttnUnpaddedGradImpl(const Context& ctx,
                                const DenseTensor& q,
@@ -236,11 +241,7 @@ void FlashAttnUnpaddedGradKernel(const Context& ctx,
     const int64_t total_k = k.dims()[0];
     const int64_t num_heads_k = k.dims()[1];
 
-    // TODO(umiswing): add deterministic in fa2.
-    // int num_splits = 0;  // 0 for an internal heuristic, which is optimal
-    // if (FLAGS_cudnn_deterministic) {
-    //   num_splits = 1;
-    // }
+    int num_splits = get_num_split();
 
     // TODO(umiswing): add shape check
     PADDLE_ENFORCE_EQ(
@@ -294,6 +295,7 @@ void FlashAttnUnpaddedGradKernel(const Context& ctx,
                                             params.scale,
                                             params.causal,
                                             params.is_bf16,
+                                            num_splits,
                                             stream,
                                             params.seed,
                                             params.offset);
@@ -401,6 +403,8 @@ void FlashAttnGradKernel(const Context& ctx,
     VLOG(10) << "FlashAttn bwd seed: " << params.seed
              << ", offset: " << params.offset;
 
+    int num_splits = get_num_split();
+
     bool succ = phi::dynload::flash_attn_bwd(dout.data(),
                                              q.data(),
                                              k.data(),
@@ -426,6 +430,7 @@ void FlashAttnGradKernel(const Context& ctx,
                                              params.scale,
                                              params.causal,
                                              params.is_bf16,
+                                             num_splits,
                                              stream,
                                              params.seed,
                                              params.offset);

test/legacy_test/test_flash_attention_deterministic.py

@@ -0,0 +1,208 @@
+# Copyright (c) 2023 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import re
+import unittest
+
+import numpy as np
+
+import paddle
+import paddle.nn.functional as F
+from paddle.device import core
+from paddle.nn.functional.flash_attention import (
+    flash_attention,
+    scaled_dot_product_attention,
+)
+
+
+def get_cuda_version():
+    result = os.popen("nvcc --version").read()
+    regex = r'release (\S+),'
+    match = re.search(regex, result)
+    if match:
+        num = str(match.group(1))
+        integer, decimal = num.split('.')
+        return int(integer) * 1000 + int(float(decimal) * 10)
+    else:
+        return -1
+
+
+def attention_naive(q, k, v, causal=False):
+    qt = paddle.transpose(q, [0, 2, 1, 3])
+    kt = paddle.transpose(k, [0, 2, 1, 3])
+    vt = paddle.transpose(v, [0, 2, 1, 3])
+    scale = 1.0 / np.sqrt(q.shape[-1])
+    s = paddle.matmul(qt, paddle.transpose(kt, [0, 1, 3, 2]))
+    s = paddle.scale(s, scale)
+    p = (
+        paddle.incubate.softmax_mask_fuse_upper_triangle(s)
+        if causal
+        else F.softmax(s)
+    )
+    o = paddle.matmul(p, vt)
+    return paddle.transpose(o, [0, 2, 1, 3])
+
+
+is_sm8x = (
+    core.is_compiled_with_cuda()
+    and paddle.device.cuda.get_device_capability()[0] == 8
+    and paddle.device.cuda.get_device_capability()[1] >= 0
+)
+
+is_sm90 = (
+    core.is_compiled_with_cuda()
+    and paddle.device.cuda.get_device_capability()[0] == 9
+    and paddle.device.cuda.get_device_capability()[1] == 0
+)
+
+is_sm_supported = is_sm8x or is_sm90
+
+
+@unittest.skipIf(
+    not core.is_compiled_with_cuda()
+    or get_cuda_version() < 11040
+    or not is_sm_supported,
+    "core is not compiled with CUDA and cuda version need larger than or equal to 11.4"
+    "and device's compute capability must be 8.x or 90",
+)
+class TestFlashAttentionAPIFlag(unittest.TestCase):
+    def setUp(self):
+        self.place = paddle.CUDAPlace(0)
+        self.shape = (2, 128, 8, 16)
+        self.dtype = 'float16'
+        self.dropout = 0.0
+        self.causal = False
+        self.return_softmax = False
+        self.use_sdp_kernel = False
+        self.use_sdp_api = False
+
+    def flash_attn_compute(self, query, key, value):
+        # test dynamic
+        paddle.disable_static()
+
+        q = paddle.to_tensor(
+            query, place=self.place, dtype=self.dtype, stop_gradient=False
+        )
+        k = paddle.to_tensor(
+            key, place=self.place, dtype=self.dtype, stop_gradient=False
+        )
+        v = paddle.to_tensor(
+            value, place=self.place, dtype=self.dtype, stop_gradient=False
+        )
+
+        q_ = paddle.to_tensor(
+            query, place=self.place, dtype=self.dtype, stop_gradient=False
+        )
+        k_ = paddle.to_tensor(
+            key, place=self.place, dtype=self.dtype, stop_gradient=False
+        )
+        v_ = paddle.to_tensor(
+            value, place=self.place, dtype=self.dtype, stop_gradient=False
+        )
+
+        if self.use_sdp_kernel:
+            with paddle.nn.functional.sdp_kernel(
+                enable_math=self.enable_math,
+                enable_flash=self.enable_flash,
+                enable_mem_efficient=self.enable_mem_efficient,
+            ):
+                if self.use_sdp_api:
+                    out = scaled_dot_product_attention(
+                        q, k, v, None, self.dropout, self.causal
+                    )
+                else:
+                    out, _ = flash_attention(
+                        q, k, v, self.dropout, self.causal, self.return_softmax
+                    )
+
+        else:
+            out, _ = flash_attention(
+                q, k, v, self.dropout, self.causal, self.return_softmax
+            )
+        out_ = attention_naive(q_, k_, v_, self.causal)
+
+        out.backward()
+        out_.backward()
+
+        self.assertEqual(q.grad.shape, q.shape)
+        self.assertEqual(q_.grad.shape, q.shape)
+
+        np.testing.assert_allclose(
+            q.grad.numpy(), q_.grad.numpy(), rtol=5e-03, atol=1e-03
+        )
+
+        return out, out_, q.grad.numpy(), k.grad.numpy(), v.grad.numpy()
+
+    def test_all_flag(self):
+        paddle.set_flags({'FLAGS_cudnn_deterministic': 1})
+        query = np.random.random(self.shape)
+        key = np.random.random(self.shape)
+        value = np.random.random(self.shape)
+
+        out1, out1_, q_grad1, k_grad1, v_grad1 = self.flash_attn_compute(
+            query, key, value
+        )
+
+        np.testing.assert_allclose(out1.numpy(), out1_, rtol=5e-03, atol=1e-03)
+
+        out2, out2_, q_grad2, k_grad2, v_grad2 = self.flash_attn_compute(
+            query, key, value
+        )
+        self.assertTrue(np.equal(out1.numpy(), out2.numpy()).all())
+        self.assertTrue(np.equal(q_grad1, q_grad2).all())
+        self.assertTrue(np.equal(k_grad1, k_grad2).all())
+        self.assertTrue(np.equal(v_grad1, v_grad2).all())
+        paddle.set_flags({'FLAGS_cudnn_deterministic': 0})
+
+
+class TestFlashAttentionAPIFlagTest1(TestFlashAttentionAPIFlag):
+    def setUp(self):
+        self.place = paddle.CUDAPlace(0)
+        self.shape = (2, 128, 8, 16)
+        self.dtype = paddle.float16
+        self.dropout = 0.0
+        self.causal = False
+        self.return_softmax = False
+        self.use_sdp_kernel = False
+
+
+class TestFlashAttentionAPIFlagTest2(TestFlashAttentionAPIFlag):
+    def setUp(self):
+        self.place = paddle.CUDAPlace(0)
+        self.shape = (8, 1024, 16, 256)
+        self.dtype = paddle.float16
+        self.dropout = 0.0
+        self.causal = False
+        self.return_softmax = False
+        self.use_sdp_kernel = False
+
+
+class TestSDPAttentionAPIFlagTest(TestFlashAttentionAPIFlag):
+    def setUp(self):
+        self.place = paddle.CUDAPlace(0)
+        self.shape = (8, 1024, 16, 128)
+        self.dtype = paddle.float16
+        self.dropout = 0.0
+        self.causal = False
+        self.return_softmax = False
+        self.use_sdp_kernel = True
+        self.use_sdp_api = True
+        self.enable_math = True
+        self.enable_flash = False
+        self.enable_mem_efficient = False
+
+
+if __name__ == '__main__':
+    unittest.main()