* CUDA: Fix data-races when reusing block_reduce
block_reduce currently doesn't resync after reading from SMEM, causing
potential data-races when reusing SMEM for multiple reductions.
One may consider simply always adding this in block_reduce, but this
comes at a potential perf cost
* double-buffering for single-row softmax
* double-buffering for norm as well
* Add comment
* Add explanatory comment to block_reduce
* Specify need for + do memory barrier only in multi-warp scenario
* Implement review-suggestion from @gaugarg-nv
* 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
* CUDA: Refactor and expose two_stage_warp_reduce_* function
* Use `two_stage_warp_reduce` also in softmax kernel, move smem out of it
Moving smem out of `__device__` function to `__global__` function
allows for explicit smem reuse, as either compiler or cuda rt seem to not
free it afterwards (`cudaFuncSetAttribute` fails when not accounting for
it once for each call to two_stage_warp_reduce)
* Update ggml/src/ggml-cuda/common.cuh
Co-authored-by: Aman Gupta <amangupta052@gmail.com>
* Use two_stage_warp_reduce in group_norm_f32
* Use two_stage_warp_reduce in rms_norm_f32
* Fix smem calculation which expects bytes
* Make `two_stage_warp_reduce` accept all values warp_reduce accepts
Also integrate it into norm_f32 function
* Use two_stage_warp_reduce in l2_norm_f32
* Use type traits for block reduction for better legibility
Also adresss other requests by @am17an such as variable renaming
* Make norm tests cover all cuda paths
* Mark columns % WARP_SIZE !=0 as supported for RMS_NORM_BACK
Unit-tests passed locally, let's see if they pass in the CI as well
* Use `enum class` for `block_reduce_method`
This is more type-safe than plain enum
* Rename variables as suggested in code review by @am17an
* Rename two_stage_warp_reduce -> block_reduce
* Fix trailing whitespace in common.cuh
* Make condition of static_assert type-dependent
This delays evaluation until the template is actually instantiated.
Otherwise, some compilers may evaluate the assert when parsing the
template, resulting in build errors as observed here:
https://github.com/ggml-org/llama.cpp/actions/runs/20960323123/job/60235530068?pr=18785
* Inline definitions
---------
Co-authored-by: Aman Gupta <amangupta052@gmail.com>
* Add fastdiv, use it in modulo and use modulo in rms_norm_f32
Fastdiv is much faster way to do integer division, which was identified
as bottleneck in rms_norm_f32
* Support more `block_size` values in `rms_norm_f32`
This makes us more flexible in selecting the optimal threads w.r.t
paralellizing across a col vs. launch-overheads of threads and mio
throttles
* Update ggml/src/ggml-cuda/common.cuh
Co-authored-by: Johannes Gäßler <johannesg@5d6.de>
* Replace modulo with fastmodulo in `rms_norm_f32`
* Use `BinPackArguments=true` for formating function calls
Will file a separate PR to adjust .clang-format file
* Update ggml/src/ggml-cuda/common.cuh
Co-authored-by: Johannes Gäßler <johannesg@5d6.de>
* Use uint3 for both `fastdiv` and `fastmodulo`
The compiler seems to reliably optimize away the unused .z component in
the fastdiv use-case, see https://godbolt.org/z/rx8KPrKr3
* More constrained type declarations
Co-authored-by: Johannes Gäßler <johannesg@5d6.de>
* Rename fastdiv and fastmodulo variables to shared variable name
As suggest by JohannesGaessler, this increases clarity of the intended
use
* Pack fastdiv/fastmodulo constants into uint2/uint3 objects
By packing constants to be used together into a struct, we are less
likely to make errors.
* Rename function parameter of fastmodulo
`modulo_consts` is more fitting/descriptive
---------
Co-authored-by: Johannes Gäßler <johannesg@5d6.de>
Oliver Simons