| name | running-with-buck |
| description | How to build and run GPU targets under Buck in fbcode. Use when invoking buck2 run / buck2 build for any GPU benchmark, test, or kernel — selecting the GPU architecture and CUDA version, using @mode/opt and the beta Triton modifier, passing environment variables through, and running from the right directory. Covers the general requirements plus the B200/GB200 (b200a, CUDA >= 12.8) and GB300 (b300a, CUDA >= 13.0) hardware requirements.
|
Running GPU Targets with Buck
This skill covers the mechanics of building and running GPU targets
under Buck in fbcode. It is target-agnostic: substitute your own
<buck target> and program arguments.
General requirements
- Run from
fbsource/fbcode. cd to fbsource/fbcode before
invoking Buck. The @mode/opt flags (and other @mode/... files) only
resolve when Buck is run from there.
- Use
@mode/opt. It provides the core GPU build configuration.
@mode/opt generally sets up the GPU build, but some tritonbench targets
still pass -c fbcode.enable_gpu_sections=true explicitly — add it if a
target's GPU sections fail to build.
- Build against the beta Triton with
-m ovr_config//triton:beta. This
directory is the beta Triton compiler. Pass this modifier so the target
builds and runs against the beta Triton in this tree rather than the
default/stable Triton — without it, changes made here are not exercised.
- Select the GPU architecture with
-c fbcode.nvcc_arch=<arch> and,
where required, the CUDA version with
-m ovr_config//third-party/cuda/constraints:<ver> (see Hardware
requirements).
- Environment variables prefix the
buck2 run and are forwarded to
the launched process:
<ENV VARS> buck2 run @mode/opt -m ovr_config//triton:beta -c fbcode.nvcc_arch=<arch> [-m ovr_config//third-party/cuda/constraints:<ver>] \
<buck target> -- <program args>
buck2 build vs buck2 run. Use buck2 build <target> to compile
only (e.g. to surface a compile failure without executing); use
buck2 run <target> -- <args> to build and run. Program arguments go
after --.
Hardware requirements
Pick the arch (and CUDA version) for the single GPU you are targeting:
| Hardware | fbcode.nvcc_arch | ovr_config//third-party/cuda/constraints:<version> |
|---|
| Hopper (H100) | h100a | (default) |
| Blackwell B200 / GB200 | b200a | >= 12.8 |
| Blackwell GB300 | b300a | >= 13.0 |
Notes:
- B200 / GB200 require CUDA
>= 12.8. Existing tritonbench targets pin
12.8; use the version your build expects.
- GB300 requires arch
b300a and CUDA >= 13.0.
- Set the CUDA version explicitly whenever a minimum applies, since the
platform default may be older than the arch requires.
Examples
Blackwell GB300 (b300a, CUDA 13.0), from fbsource/fbcode:
buck2 run @mode/opt -m ovr_config//triton:beta \
-c fbcode.nvcc_arch=b300a \
-m ovr_config//third-party/cuda/constraints:13.0 \
<buck target> -- <program args>
Blackwell B200 / GB200 (b200a, CUDA >= 12.8):
buck2 run @mode/opt -m ovr_config//triton:beta \
-c fbcode.nvcc_arch=b200a \
-m ovr_config//third-party/cuda/constraints:12.8 \
<buck target> -- <program args>
Hopper (h100a):
buck2 run @mode/opt -m ovr_config//triton:beta \
-c fbcode.nvcc_arch=h100a \
<buck target> -- <program args>
With env vars forwarded (e.g. enabling a feature for the run):
SOME_ENV=1 buck2 run @mode/opt -m ovr_config//triton:beta -c fbcode.nvcc_arch=b300a \
-m ovr_config//third-party/cuda/constraints:13.0 \
<buck target> -- <program args>
Compile only (surface a build/compile failure without running):
buck2 build @mode/opt -m ovr_config//triton:beta -c fbcode.nvcc_arch=b300a \
-m ovr_config//third-party/cuda/constraints:13.0 \
<buck target>
