Again set a few extra params in flash-attn. (#245)

* Again set a few extra params.

* Use the appropriate kernel sizes.

* Add all the kernel sizes.

* Parallel compiling.

* Reduce the amount of parallelism.

* Add the missing kernel.

* Fix a typo.

* Remove bf16 support for now.

candle-flash-attn/kernels/flash_api.cu

@@ -0,0 +1,109 @@
+#include "flash_fwd_launch_template.h"
+
+// TODO: Switch back to handling bf16.
+void run_mha_fwd(Flash_fwd_params &params, cudaStream_t stream) {
+    FWD_HEADDIM_SWITCH(params.d, [&] {
+        run_mha_fwd_<cutlass::half_t, kHeadDim>(params, stream);
+    });
+}
+
+// void run_mha_fwd(Flash_fwd_params &params, cudaStream_t stream) {
+//     FP16_SWITCH(!params.is_bf16, [&] {
+//         FWD_HEADDIM_SWITCH(params.d, [&] {
+//             run_mha_fwd_<elem_type, kHeadDim>(params, stream);
+//         });
+//     });
+// }
+
+extern "C" void run_mha(
+    void *q_ptr,
+    void *k_ptr,
+    void *v_ptr,
+    void *o_ptr,
+    void *softmax_lse_ptr,
+
+    uint32_t q_batch_stride,
+    uint32_t k_batch_stride,
+    uint32_t v_batch_stride,
+    uint32_t o_batch_stride,
+
+    uint32_t q_row_stride,
+    uint32_t k_row_stride,
+    uint32_t v_row_stride,
+    uint32_t o_row_stride,
+
+    uint32_t q_head_stride,
+    uint32_t k_head_stride,
+    uint32_t v_head_stride,
+    uint32_t o_head_stride,
+
+    uint32_t b,
+    uint32_t h,
+    uint32_t h_k,
+    uint32_t d,
+    uint32_t d_rounded,
+    float softmax_scale,
+
+    uint32_t seqlen_q,
+    uint32_t seqlen_k,
+    uint32_t seqlen_q_rounded,
+    uint32_t seqlen_k_rounded,
+
+    int is_causal
+) {
+    Flash_fwd_params params;
+    // Reset the parameters
+    memset(&params, 0, sizeof(params));
+
+    // Set the pointers and strides.
+    params.q_ptr = q_ptr;
+    params.k_ptr = k_ptr;
+    params.v_ptr = v_ptr;
+    params.o_ptr = o_ptr;
+
+    params.softmax_lse_ptr = softmax_lse_ptr;
+
+    // All stride are in elements, not bytes.
+    params.q_batch_stride = q_batch_stride;
+    params.k_batch_stride = k_batch_stride;
+    params.v_batch_stride = v_batch_stride;
+    params.o_batch_stride = o_batch_stride;
+
+    params.q_row_stride = q_row_stride;
+    params.k_row_stride = k_row_stride;
+    params.v_row_stride = v_row_stride;
+    params.o_row_stride = o_row_stride;
+    params.q_head_stride = q_head_stride;
+    params.k_head_stride = k_head_stride;
+    params.v_head_stride = v_head_stride;
+    params.o_head_stride = o_head_stride;
+
+    // Set the dimensions.
+    params.b = b;
+    params.h = h;
+    params.h_k = h_k;
+    params.h_h_k_ratio = h / h_k;
+    params.seqlen_q = seqlen_q;
+    params.seqlen_k = seqlen_k;
+    params.seqlen_q_rounded = seqlen_q_rounded;
+    params.seqlen_k_rounded = seqlen_k_rounded;
+    params.d = d;
+    params.d_rounded = d_rounded;
+    params.is_causal = is_causal;
+
+    // Set the different scale values.
+    params.scale_softmax = softmax_scale;
+    params.scale_softmax_log2 = softmax_scale * M_LOG2E;
+
+    params.p_dropout = 1.; // probability to keep
+    params.p_dropout_in_uint8_t = uint8_t(std::floor(params.p_dropout * 255.0));
+    params.rp_dropout = 1.f / params.p_dropout;
+    params.scale_softmax_rp_dropout = params.rp_dropout * params.scale_softmax;
+    params.is_bf16 = 0;
+    params.cu_seqlens_q = nullptr;
+    params.cu_seqlens_k = nullptr;
+    params.p_ptr = nullptr;
+
+    cudaStream_t stream = 0; // Use the default stream.
+    run_mha_fwd(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim128_bf16_sm80.cu

@@ -0,0 +1,19 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+// template<>
+// void run_mha_fwd_<cutlass::bfloat16_t, 128>(Flash_fwd_params &params, cudaStream_t stream) {
+//     using elem_type = cutlass::bfloat16_t;
+//     if (params.p_dropout == 1.f) {
+//         run_flash_fwd<Flash_fwd_kernel_traits<128, 128, 64, 4, false, false, elem_type>, false>(params, stream);
+//     } else {
+//         run_flash_fwd<Flash_fwd_kernel_traits<128, 128, 32, 4, false, false, elem_type>, true>(params, stream);
+//     }
+// }
+template<>
+void run_mha_fwd_<cutlass::bfloat16_t, 128>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim128<cutlass::bfloat16_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim128_fp16_sm80.cu

@@ -0,0 +1,32 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+// template<>
+// void run_mha_fwd_<cutlass::half_t, 128>(Flash_fwd_params &params, cudaStream_t stream) {
+//     using elem_type = cutlass::half_t;
+//     if (params.p_dropout == 1.f) {
+//         // Using 8 warps (128 x 128 and 256 x 64) is 28% slower for seqlen=2k
+//         run_flash_fwd<Flash_fwd_kernel_traits<128, 128, 64, 4, false, false, elem_type>, false>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<128, 128, 64, 4, true, false, elem_type>, false>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<128, 128, 64, 4, false, true, elem_type>, false>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<128, 128, 64, 4, true, true, elem_type>, false>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<128, 128, 32, 4, false, false, elem_type>, false>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<128, 64, 64, 4, false, false, elem_type>, false>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<128, 64, 128, 4, false, false, elem_type>, false>(params, stream);
+//         // 1st ones are good for H100, A100
+//         // 2nd one is good for A6000 bc we get slightly better occupancy
+//     } else {
+//         run_flash_fwd<Flash_fwd_kernel_traits<128, 128, 32, 4, false, false, elem_type>, true>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<128, 128, 32, 4, true, false, elem_type>, true>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<128, 128, 32, 4, true, true, elem_type>, true>(params, stream);
+//         // 1st one is good for H100, A100, A6000
+//     }
+// }
+
+template<>
+void run_mha_fwd_<cutlass::half_t, 128>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim128<cutlass::half_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim160_bf16_sm80.cu

@@ -0,0 +1,17 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+// template<>
+// void run_mha_fwd_<cutlass::bfloat16_t, 160>(Flash_fwd_params &params, cudaStream_t stream) {
+//     using elem_type = cutlass::bfloat16_t;
+//     BOOL_SWITCH(params.p_dropout < 1.f, Is_dropout, [&] {
+//         run_flash_fwd<Flash_fwd_kernel_traits<160, 128, 32, 4, false, false, elem_type>, Is_dropout>(params, stream);
+//     });
+// }
+template<>
+void run_mha_fwd_<cutlass::bfloat16_t, 160>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim160<cutlass::bfloat16_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim160_fp16_sm80.cu

@@ -0,0 +1,27 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+// template<>
+// void run_mha_fwd_<cutlass::half_t, 160>(Flash_fwd_params &params, cudaStream_t stream) {
+//     using elem_type = cutlass::half_t;
+//     BOOL_SWITCH(params.p_dropout < 1.f, Is_dropout, [&] {
+//         run_flash_fwd<Flash_fwd_kernel_traits<160, 128, 32, 4, false, false, elem_type>, Is_dropout>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<160, 128, 32, 4, false, true, elem_type>, Is_dropout>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<160, 128, 64, 4, false, false, elem_type>, Is_dropout>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<160, 64, 64, 4, false, false, elem_type>, Is_dropout>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<160, 128, 64, 4, false, elem_type>>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<160, 64, 128, 4, false, elem_type>>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<160, 64, 64, 4, false, elem_type>>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<160, 128, 64, 8, false, elem_type>>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<160, 128, 128, 8, false, elem_type>>(params, stream);
+//         // For A6000, no-causal, 1st is fastest. causal, 4th is fastest.
+//         // For A100, H100, 1st is fastest.
+//     });
+// }
+template<>
+void run_mha_fwd_<cutlass::half_t, 160>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim160<cutlass::half_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim192_bf16_sm80.cu

@@ -0,0 +1,16 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+// template<>
+// void run_mha_fwd_<cutlass::bfloat16_t, 192>(Flash_fwd_params &params, cudaStream_t stream) {
+//     using elem_type = cutlass::bfloat16_t;
+//     BOOL_SWITCH(params.p_dropout < 1.f, Is_dropout, [&] {
+//         run_flash_fwd<Flash_fwd_kernel_traits<192, 64, 64, 4, false, false, elem_type>, Is_dropout>(params, stream);
+//     });
+// }
+template<> void run_mha_fwd_<cutlass::bfloat16_t, 192>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim192<cutlass::bfloat16_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim192_fp16_sm80.cu

@@ -0,0 +1,27 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+// template<>
+// void run_mha_fwd_<cutlass::half_t, 192>(Flash_fwd_params &params, cudaStream_t stream) {
+//     using elem_type = cutlass::half_t;
+//     BOOL_SWITCH(params.p_dropout < 1.f, Is_dropout, [&] {
+//         run_flash_fwd<Flash_fwd_kernel_traits<192, 64, 64, 4, false, false, elem_type>, Is_dropout>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<192, 128, 32, 4, false, false, elem_type>, Is_dropout>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<192, 64, 32, 4, false, false, elem_type>, Is_dropout>(params, stream);
+//         // This one is slightly faster for causal?
+//         // run_flash_fwd<Flash_fwd_kernel_traits<192, 128, 64, 8, false, elem_type>>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<192, 128, 32, 4, false, elem_type>>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<192, 128, 64, 4, false, elem_type>>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<192, 64, 128, 4, false, elem_type>>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<192, 128, 128, 8, false, elem_type>>(params, stream);
+//     });
+//     // For A100 H100, 1st is faster with dropout, 3rd is faster without dropout
+//     // For A6000, 1st is faster when causal, 3rd is faster when not causal
+// }
+template<>
+void run_mha_fwd_<cutlass::half_t, 192>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim192<cutlass::half_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim224_bf16_sm80.cu

@@ -0,0 +1,9 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+template<> void run_mha_fwd_<cutlass::bfloat16_t, 224>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim224<cutlass::bfloat16_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim224_fp16_sm80.cu

@@ -0,0 +1,9 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+template<> void run_mha_fwd_<cutlass::half_t, 224>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim224<cutlass::half_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim256_bf16_sm80.cu

@@ -0,0 +1,9 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+template<> void run_mha_fwd_<cutlass::bfloat16_t, 256>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim256<cutlass::bfloat16_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim256_fp16_sm80.cu

@@ -0,0 +1,9 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+template<> void run_mha_fwd_<cutlass::half_t, 256>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim256<cutlass::half_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim32_bf16_sm80.cu

@@ -0,0 +1,10 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+template<>
+void run_mha_fwd_<cutlass::bfloat16_t, 32>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim32<cutlass::bfloat16_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim32_fp16_sm80.cu

@@ -20,94 +20,4 @@
 template<>
 void run_mha_fwd_<cutlass::half_t, 32>(Flash_fwd_params &params, cudaStream_t stream) {
     run_mha_fwd_hdim32<cutlass::half_t>(params, stream);
-}
-
-
-extern "C" void run_mha(
-    void *q_ptr,
-    void *k_ptr,
-    void *v_ptr,
-    void *o_ptr,
-    void *softmax_lse_ptr,
-
-    uint32_t q_batch_stride,
-    uint32_t k_batch_stride,
-    uint32_t v_batch_stride,
-    uint32_t o_batch_stride,
-
-    uint32_t q_row_stride,
-    uint32_t k_row_stride,
-    uint32_t v_row_stride,
-    uint32_t o_row_stride,
-
-    uint32_t q_head_stride,
-    uint32_t k_head_stride,
-    uint32_t v_head_stride,
-    uint32_t o_head_stride,
-
-    uint32_t b,
-    uint32_t h,
-    uint32_t h_k,
-    uint32_t d,
-    uint32_t d_rounded,
-    float softmax_scale,
-
-    uint32_t seqlen_q,
-    uint32_t seqlen_k,
-    uint32_t seqlen_q_rounded,
-    uint32_t seqlen_k_rounded,
-
-    int is_causal
-) {
-    Flash_fwd_params params;
-    // Reset the parameters
-    memset(&params, 0, sizeof(params));
-
-    // Set the pointers and strides.
-    params.q_ptr = q_ptr;
-    params.k_ptr = k_ptr;
-    params.v_ptr = v_ptr;
-    params.o_ptr = o_ptr;
-
-    params.softmax_lse_ptr = softmax_lse_ptr;
-
-    // All stride are in elements, not bytes.
-    params.q_batch_stride = q_batch_stride;
-    params.k_batch_stride = k_batch_stride;
-    params.v_batch_stride = v_batch_stride;
-    params.o_batch_stride = o_batch_stride;
-
-    params.q_row_stride = q_row_stride;
-    params.k_row_stride = k_row_stride;
-    params.v_row_stride = v_row_stride;
-    params.o_row_stride = o_row_stride;
-    params.q_head_stride = q_head_stride;
-    params.k_head_stride = k_head_stride;
-    params.v_head_stride = v_head_stride;
-    params.o_head_stride = o_head_stride;
-
-    // Set the dimensions.
-    params.b = b;
-    params.h = h;
-    params.h_k = h_k;
-    params.h_h_k_ratio = h / h_k;
-    params.seqlen_q = seqlen_q;
-    params.seqlen_k = seqlen_k;
-    params.seqlen_q_rounded = seqlen_q_rounded;
-    params.seqlen_k_rounded = seqlen_k_rounded;
-    params.d = d;
-    params.d_rounded = d_rounded;
-    params.is_causal = is_causal;
-
-    // Set the different scale values.
-    params.scale_softmax = softmax_scale;
-    params.scale_softmax_log2 = softmax_scale * M_LOG2E;
-
-    params.p_dropout = 1.; // probability to keep
-    params.p_dropout_in_uint8_t = uint8_t(std::floor(params.p_dropout * 255.0));
-    params.rp_dropout = 1.f / params.p_dropout;
-    params.scale_softmax_rp_dropout = params.rp_dropout * params.scale_softmax;
-
-    cudaStream_t stream = 0; // Use the default stream.
-    run_mha_fwd_<cutlass::half_t, 32>(params, stream);
-}
+}

candle-flash-attn/kernels/flash_fwd_hdim64_bf16_sm80.cu

@@ -0,0 +1,19 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+// template<>
+// void run_mha_fwd_<cutlass::bfloat16_t, 64>(Flash_fwd_params &params, cudaStream_t stream) {
+//     using elem_type = cutlass::bfloat16_t;
+//     if (params.p_dropout == 1.f) {
+//         run_flash_fwd<Flash_fwd_kernel_traits<64, 128, 64, 4, true, false, elem_type>, false>(params, stream);
+//     } else {
+//         run_flash_fwd<Flash_fwd_kernel_traits<64, 128, 64, 4, false, false, elem_type>, true>(params, stream);
+//     }
+// }
+template<>
+void run_mha_fwd_<cutlass::bfloat16_t, 64>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim64<cutlass::bfloat16_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim64_fp16_sm80.cu

@@ -0,0 +1,26 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+// template<>
+// void run_mha_fwd_<cutlass::half_t, 64>(Flash_fwd_params &params, cudaStream_t stream) {
+//     using elem_type = cutlass::half_t;
+//     if (params.p_dropout == 1.f) {
+//         // Using 8 warps is 18% slower for seqlen=2k, 2 warps is 5% slower
+//         // Using block size (64 x 256) is 27% slower for seqlen=2k
+//         // Using block size (256 x 64) is 85% slower for seqlen=2k, because of register spilling
+//         run_flash_fwd<Flash_fwd_kernel_traits<64, 128, 128, 4, false, false, elem_type>, false>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<64, 128, 64, 4, true, false, elem_type>, false>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<64, 128, 64, 4, true, true, elem_type>, false>(params, stream);
+//     } else {
+//         run_flash_fwd<Flash_fwd_kernel_traits<64, 128, 64, 4, false, false, elem_type>, true>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<64, 128, 64, 4, true, true, elem_type>, true>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<64, 128, 64, 4, true, false, elem_type>, true>(params, stream);
+//     }
+// }
+template<>
+void run_mha_fwd_<cutlass::half_t, 64>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim64<cutlass::half_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim96_bf16_sm80.cu

@@ -0,0 +1,17 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+// template<>
+// void run_mha_fwd_<cutlass::bfloat16_t, 96>(Flash_fwd_params &params, cudaStream_t stream) {
+//     using elem_type = cutlass::bfloat16_t;
+//     BOOL_SWITCH(params.p_dropout < 1.f, Is_dropout, [&] {
+//         run_flash_fwd<Flash_fwd_kernel_traits<96, 128, 64, 4, true, false, elem_type>, Is_dropout>(params, stream);
+//     });
+// }
+template<>
+void run_mha_fwd_<cutlass::bfloat16_t, 96>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim96<cutlass::bfloat16_t>(params, stream);
+}

candle-flash-attn/kernels/flash_fwd_hdim96_fp16_sm80.cu

@@ -0,0 +1,23 @@
+// Copyright (c) 2023, Tri Dao.
+
+// Splitting the different head dimensions to different files to speed up compilation.
+
+#include "flash_fwd_launch_template.h"
+
+// template<>
+// void run_mha_fwd_<cutlass::half_t, 96>(Flash_fwd_params &params, cudaStream_t stream) {
+//     using elem_type = cutlass::half_t;
+//     BOOL_SWITCH(params.p_dropout < 1.f, Is_dropout, [&] {
+//         run_flash_fwd<Flash_fwd_kernel_traits<96, 128, 64, 4, true, false, elem_type>, Is_dropout>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<96, 128, 64, 4, true, true, elem_type>, Is_dropout>(params, stream);
+//         // This 3rd one is good for H100, and A100, A6000
+//         run_flash_fwd<Flash_fwd_kernel_traits<96, 128, 64, 4, false, false, elem_type>, Is_dropout>(params, stream);
+//         run_flash_fwd<Flash_fwd_kernel_traits<96, 128, 64, 4, false, true, elem_type>, Is_dropout>(params, stream);
+//         // These two are always slower
+//         // run_flash_fwd<Flash_fwd_kernel_traits<96, 128, 128, 4, true, elem_type>>(params, stream);
+//         // run_flash_fwd<Flash_fwd_kernel_traits<96, 64, 128, 4, true, elem_type>>(params, stream);
+//     });
+// }
+template<> void run_mha_fwd_<cutlass::half_t, 96>(Flash_fwd_params &params, cudaStream_t stream) {
+    run_mha_fwd_hdim96<cutlass::half_t>(params, stream);
+}