* 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>
* musa: fix build warnings
Signed-off-by: Xiaodong Ye <xiaodong.ye@mthreads.com>
* fix warning: comparison of integers of different signs: 'const int' and 'unsigned int' [-Wsign-compare]
Signed-off-by: Xiaodong Ye <xiaodong.ye@mthreads.com>
---------
Signed-off-by: Xiaodong Ye <xiaodong.ye@mthreads.com>
* Factor out `reduce_rows_f32` from common.cuh
This increases iteration cycle speed by not having to recompile
every kernel all the time
* Hide memory-latency by loop unrolling in reduce_rows_f32
* Further optimizations to `reduce_rows_f32`
1. Increase threadblock size to better hide latency of memory requests.
As a consequence of bigger threadblocks, do 2-step summation, using
shared memory to communicate results between invocations
2. Use sum_temp array to reduce waits on sum
3. Adjust num_unroll to reflext bigger threadblock
4. Improve default block_dims, increase support for more block_dims
* Add perf tests for `reduce_rows_f32` kernel
* Add heuristic to toggle 128/512 threads based on sm count
Break even point was the minimum of the following multiples.
| GPU Model | Nrow SM Count Multiple |
| ----------- | ----------- |
| RTX 4000 SFF ADA | 2.0x |
| RTX 6000 ADA | 2.5x |
| RTX PRO 6000 Blackwell Max-Q | 3.04x |
| RTX PRO 4500 Blackwell | 3.15x |
* Ensure perf gains also for small ncols and large nrows
Alternative to this, one could have also made the number of unrollings
template-able, but that would require compiling the kernel multiple
times, increasing binary size unnecessarily
* Modify perf and unit-tests
* Apply auto-formatting by clang
* Fix CI build failure
See https://github.com/ggml-org/llama.cpp/actions/runs/16798370266/job/47573716079?pr=15132#step:7:486
Building with VS generator worked though.
* Remove sm_count property from `ggml_backend_cuda_context`
Requested by @JohannesGaessler, and should fix remaining CI issues as a
side-effect
* Add CUB-based implementation for GGML_OP_MEAN
Currently this branch is only executed for nrows==1
* Add heuristics to execute CUB branch only when it brings perf
Heuristics were determined on the following HW:
* RTX 4000 SFF ADA
* RTX 6000 ADA
* RTX PRO 6000 Blackwell Max-Q
* RTX PRO 4500 Blackwell
* Add unit-test for CUB-based mean
Tests should run with CUDA Graphs enabled per default on NVGPUs
* Rename `USE_CUB` to `GGML_CUDA_USE_CUB`
Suggested by @JohannesGaessler
* Unindent Preprocessor directives
See
https://github.com/ggml-org/llama.cpp/pull/15132#discussion_r2269213506
Oliver Simons
R0CKSTAR