Programmatic Dependent Launch (PDL) for more performance on newer NVIDIA GPUs (Hopper+) (#22522)

* Adds initial PDL setup.

* Adds PDL barriers based on simple heuristic: place "sync" before first input pointer access, and "launch" after last write, e.g. to tensors like dst.

* Further optimization pass of the first half of kernels

* Optimized PDL barriers for the second batch of kernels

* Further refinements after rebase.

* Moves pdl logic to separate function, removes some whitespace

* Strips post-hoc PDL logic

* Adds stream capture PDL setup. Enrolls quantize_q8_1 to leverage pdl to
overlap execution with previous kernels

* Enrolls mul_mat_vec_q, rms_norm_f32 and k_bin_bcast (partly) into PDL

* Enrolls mmvf, rope, set-rows and topk kernels for gpt-oss into PDL

* Introduce ggml_cuda_kernel_launch, to abstract away cudaLaunchKernelEx,
to enable hip/musa compatibility

* Enrolls cpy_scalar_contiguous, k_get_rows_float and rms_norm_f32

* Enrolls flash_attn_combine_results

* Fix: Drops needless and broken check of CUDA arch for PDL. PDL either
works or is without effect.

* Enrolls flash-attention kernels to pdl

* Fix: inlines ggml_cuda_kernel_launch, and uses perfect forwarding for
kernels args. This fixes PDL.

* Perf: Enrolls k_bin_bcast variadic template invocation into PDL, via
and template alias and template expansion

* Enrolls all remaining kernels for qwen3-coder-next into PDL

* Remove all PDL LC calls to create a baseline

* Added LC according to internal guidance and tested kernel performance.

* Enrols missing qwen3-5 kernels passively into PDL.

* Kernel optimizations (LC signals) for qwen3.5

* Enrolls ssm-scan kernels into PDL

* Adds GGML_CUDA_PDL command line option to toggle PDL.

* Fix: Ada and lower compilation by guarding PDL calls correctly

* Cleanup: Removes commented out GGML_CUDA_PDL_LC

* Cleanup: Removes experimental comments

* Adds 90-virtual to build script so that Hopper GPUs can leverage PDL.

* Adds stricter checks to enable PDL, adds env-check to disable it, and removes now superfluous compile option to enable PDL.

* Fix: Correct PDL en/disablement based on device-side arch check. Host
side check is UB. Required moving from macros to inlined functions

* Fix: default-disable PDL. Enable by setting GGML_CUDA_ENABLE_PDL=1

* Enable PDL by default for Hopper+ devices

* Enrolls softcap_f32 and two flash_attn kernels into PDL.

* Improves flash attn PDL barrier placement

* Fix: Perf regression on ada; excludes ada and below from PDL launches

* Improves some sync barrier placements

* Drops superfluous constructor

* Adds #endif guard comments

* Reverts experimental change to top-k-moe.cu, which moved expensive allocations
in front of the PDL barrier. It did not have a meaningful impact.

* Exchanges GGML_CUDA_DISABLE_PDL with GGML_CUDA_PDL. IFF GGML_CUDA_PDL=0
PDL is disabled

* Revert "Drops superfluous constructor". Adds const to remaining
arguments

This reverts commit 12b1d250da0089ae02a9bb71bbb3fd6d70f6f2f1.

* Cleanup: Removes and fixes some comments and whitespace

* Clarifies comment of sync-barrier position

* Relocates and refactors PDL launch functions and accessories

* Adds error checking to the regular kernel launch path

* Drops "auto" in favor of "ggml_cuda_kernel_params"

* Adds "const" to ggml_cuda_kernel_launch_params

* [Whitespace] Adds final newline to common.cuh to make editorconfig CI job happy

ggml/src/ggml-cuda/getrows.cu

@@ -11,6 +11,7 @@ static __global__ void k_get_rows(
         /*const size_t nb00,*/ const size_t nb01, const size_t nb02, const size_t nb03,
         const size_t s10, const size_t s11, const size_t s12/*, const size_t s13*/) {
 
+    ggml_cuda_pdl_sync();
     for (int64_t z = blockIdx.z; z < ne11*(int64_t)ne12_fdv.z; z += gridDim.z) {
         for (int64_t i00 = 2*(blockIdx.y*blockDim.x + threadIdx.x); i00 < ne00; i00 += gridDim.y*blockDim.x) {
             // The x and y dimensions of the grid are swapped because the maximum allowed grid size for x is higher.
@@ -48,6 +49,8 @@ static __global__ void k_get_rows_float(
         /*const size_t nb00,*/ const size_t nb01, const size_t nb02, const size_t nb03,
         const size_t s10, const size_t s11, const size_t s12/*, const size_t s13*/) {
 
+    ggml_cuda_pdl_lc();
+    ggml_cuda_pdl_sync();
     for (int64_t z = blockIdx.z; z < ne11*(int64_t)ne12_fdv.z; z += gridDim.z) {
         for (int64_t i00 = blockIdx.y*blockDim.x + threadIdx.x; i00 < ne00; i00 += gridDim.y*blockDim.x) {
             // The x and y dimensions of the grid are swapped because the maximum allowed grid size for x is higher.
@@ -83,6 +86,7 @@ static __global__ void k_get_rows_back_float(
 
     float sum = 0.0f;
 
+    ggml_cuda_pdl_sync();
     for (int64_t i = 0; i < nrows_grad; ++i) {
         if (rows[i] != dst_row) {
             continue;
@@ -156,7 +160,8 @@ static void get_rows_cuda_float(
     GGML_ASSERT(ne11 <= std::numeric_limits<uint32_t>::max() / ne12);
     const uint3 ne12_fdv = init_fastdiv_values(ne12);
 
-    k_get_rows_float<<<block_nums, block_dims, 0, stream>>>(
+    const ggml_cuda_kernel_launch_params launch_params = ggml_cuda_kernel_launch_params{block_nums, block_dims, 0, stream};
+    ggml_cuda_kernel_launch(k_get_rows_float<src0_t, dst_t>, launch_params,
         src0_d, src1_d, dst_d,
         ne00, /*ne01, ne02, ne03,*/
         /*ne10,*/ ne11, ne12_fdv, /*ne13,*/