7 Commits
Author SHA1 Message Date
3fc4e10527 sched : reintroduce less synchronizations during split compute (#20793)
* CUDA:  Improve performance via less synchronizations between token (#17795)

* Adds CPU-to-CUDA copy capability to
ggml_backend_cuda_cpy_tensor_async()

* Adds function to relax sync requirements between input copies on
supported backends (CUDA for now)

* Exchanges synchronous copy with async copy function.

* Adds macro guards to allow compilation in non-CUDA builds

* Reworked backend detection in ggml-backend.cpp to avoid linking
conflicts

* Relax requirement of checks in async CUDA copies from backend and buffer type to just buffer type, to avoid linking issues

* Minor cleanup

* Makes opt-in to relax use of explicit syncs more general. Backends like
vulkan which require a synchronization between HtoD copies and graph
execution could also adopt this change now.

* Reintroduces stricter check for CPU->CUDA backend async copy via
GGML_DEVICE_TYPE_CPU.

* Corrects initialization of ggml_backend_sync_mode in
ggml_backend_sched_split initialization

* Simplifies synchronizations to adhere to `saaasg` pattern.

* Apply suggestion from @ggerganov (src->buffer to buf_src)

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

* Apply suggestion from @ggerganov (src->buffer to buf_src) v2

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

* Apply suggestions from @johannesgaessler code review

Co-authored-by: Johannes Gäßler <johannesg@5d6.de>

* Adds single-GPU synchronizations to multi-GPU settings to fix hip backend pipeline parallel bugs.

* Scheduler Hardening: Exclude hip/MUSA from copy_from_host CPU split ->
GPU split optimization

* Scheduler Hardening: Re-adding original additional synchronizations for
non-async backends

* Adds disclaimer to hip/musa exclusion of copy_from_host. Highlights that it is out of
precaution, but that no perf-impact is visible, and that it can be
revisited separately anytime.

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
Co-authored-by: Johannes Gäßler <johannesg@5d6.de>
2026-06-26 17:18:30 +03:00
9e58d4d692 Avoid PDL race conditions by disabling __restrict__ when PDL is used (#24030)
* Removes __restrict__ from PDL kernel headers due to incompatibility with
PDL. Adds preprocessor directives based on arch in kernel body to add
__restrict__ to retain performance on older architectures.

* Simplifies new __restrict__ usage via macro

* Add hopper to PDL __restrict__ fix.

Co-authored-by: Oliver Simons <osimons@nvidia.com>

---------

Co-authored-by: Oliver Simons <osimons@nvidia.com>
2026-06-03 13:56:42 +02:00
Andreas KieslingerandGitHub 241cbd41d2 cuda : disables launch_fattn PDL enrollment due to compiler bug (#23825) 2026-05-29 07:46:10 +03:00
Andreas KieslingerandGitHub e947228222 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
2026-05-20 13:59:02 +02:00
2cd20b72ed CUDA: Improve performance via less synchronizations between token (#17795)
* Adds CPU-to-CUDA copy capability to
ggml_backend_cuda_cpy_tensor_async()

* Adds function to relax sync requirements between input copies on
supported backends (CUDA for now)

* Exchanges synchronous copy with async copy function.

* Adds macro guards to allow compilation in non-CUDA builds

* Reworked backend detection in ggml-backend.cpp to avoid linking
conflicts

* Relax requirement of checks in async CUDA copies from backend and buffer type to just buffer type, to avoid linking issues

* Minor cleanup

* Makes opt-in to relax use of explicit syncs more general. Backends like
vulkan which require a synchronization between HtoD copies and graph
execution could also adopt this change now.

* Reintroduces stricter check for CPU->CUDA backend async copy via
GGML_DEVICE_TYPE_CPU.

* Corrects initialization of ggml_backend_sync_mode in
ggml_backend_sched_split initialization

* Simplifies synchronizations to adhere to `saaasg` pattern.

* Apply suggestion from @ggerganov (src->buffer to buf_src)

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

* Apply suggestion from @ggerganov (src->buffer to buf_src) v2

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
2026-03-05 13:53:21 +02:00
39509fb082 cuda : CUDA Graph Compute Function Refactor (precursor for performance improvements) (#11042)
* Refactor: Moves cuda graph executable update step to separate function.

* Refactor: Moves cuda graph update check to separate function.

* Refactor: Moves cuda graph maintenance (update or adjusting copy parameters) to separate function for improved readability.

* Fix: Adds missing reference to maintain_cuda_graph() definition.

* Refactor: Improves structure and abstractions by moving CUDA graph evaluation and capture to its own function.

* Refactor: Moves node graph checks and copy ops into individual function for improved readability.

* Refactor: Removes code permanently excluded from compilation to increase readability.

* Style: Adds missing newline

* Style: Consolidates several neighboring '#ifdef USE_CUDA_GRAPH' into a single one

* Refactor: Makes 'cuda_graph_update_required' a local variable

* remove double lines between functions

---------

Co-authored-by: slaren <slarengh@gmail.com>
2025-01-13 16:45:53 +01:00
Andreas KieslingerandGitHub 750cb3e246 CUDA: rename macros to avoid conflicts with WinAPI (#10736)
* Renames NVIDIA GPU-architecture flags to avoid name clashes with WinAPI. (e.g. CC_PASCAL, GPU architecture or WinAPI pascal compiler flag?)

* Reverts erroneous rename in SYCL-code.

* Renames GGML_CUDA_MIN_CC_DP4A to GGML_CUDA_CC_DP4A.

* Renames the rest of the compute capability macros for consistency.
2024-12-10 18:23:24 +01:00