feat: add FFI_USE_CUDA_SUPRASEAL env variable (#425)

Make it possible to build the FFI with SupraSeal enabled, which should
lead to better performance during C2.

Author: vmx

.circleci/config.yml

@@ -107,6 +107,19 @@ jobs:
       - run: cd rust && cargo install cargo-lipo
       - build_project
       - compile_tests
+
+  # SupraSeal pulls in a C++ code base, make sure everything compiles properly.
+  build_linux_supraseal:
+    executor: golang
+    resource_class: medium
+    working_directory: ~/go/src/github.com/filecoin-project/filecoin-ffi
+    steps:
+      - configure_environment_variables
+      - prepare
+      - run:
+          name: Build project with `FFI_USE_CUDA_SUPRASEAL=1`
+          command: FFI_BUILD_FROM_SOURCE=1 FFI_USE_CUDA_SUPRASEAL=1 make
+
   publish_linux_x86_64_staticlib:
     executor: golang
     resource_class: medium
@@ -172,6 +185,7 @@ workflows:
       - build_and_test_aarch64_linux_cgo_bindings:
           run_leak_detector: false
       - build_darwin_cgo_bindings
+      - build_linux_supraseal
       - publish_linux_x86_64_staticlib:
           filters:
             tags:
@@ -208,7 +222,12 @@ commands:
           condition: << parameters.linux >>
           steps:
             - run: sudo apt-get update
-            - run: sudo apt-get install --no-install-recommends -y valgrind ocl-icd-opencl-dev libssl-dev libhwloc-dev nvidia-cuda-toolkit
+            - run: sudo apt-get install --no-install-recommends -y valgrind ocl-icd-opencl-dev libssl-dev libhwloc-dev nvidia-cuda-toolkit g++-10
+            - run:
+                name: Downgrade to GCC 10, as CUDA 11 doesn't play nice with GCC 11
+                command: |
+                  sudo update-alternatives --install /usr/bin/c++ c++ /usr/bin/g++-10 10
+                  sudo update-alternatives --set c++ /usr/bin/g++-10
       - when:
           condition: << parameters.darwin >>
           steps:

README.md

@@ -48,6 +48,8 @@ rm .install-filcrypto \
 
 CUDA for GPU support is now enabled by default in the proofs library.  This feature can optionally be replaced by OpenCL by using `FFI_USE_OPENCL=1` set in the environment when building from source.  Alternatively, if the CUDA toolkit (such as `nvcc`) cannot be located in the environment, OpenCL support is used instead.  To disable GPU support entirely, set `FFI_USE_GPU=0` in the environment when building from source.
 
+There is experimental support for faster C2 named "SupraSeal". To enable it, set `FFI_USE_CUDA_SUPRASEAL=1`. It's specific to CUDA and won't work with OpenCL.
+
 ```shell
 rm .install-filcrypto \
     ; make clean \

install-filcrypto

@@ -176,11 +176,15 @@ build_from_source() {
     # Check if GPU support is disabled.
     if [ "${FFI_USE_GPU}" == "0" ]; then
         gpu_flags=""
+    elif [ "${FFI_USE_CUDA_SUPRASEAL}" == "1" ]; then
+        # If SupraSeal is enabled, just use the `cuda-supraseal` eature and
+        # nothing else GPU related.
+        gpu_flags=",cuda-supraseal"
     else
-        # If not, default to CUDA support where possible.
-        # First ensure that nvcc (as part of the CUDA toolkit) is
-        # available -- if it's not warn that we are defaulting GPU to
-        # OpenCL instead.
+        # If GPUs are enabled and SupraSeal is not, default to CUDA support
+        # where possible.
+        # First ensure that nvcc (as part of the CUDA toolkit) is available --
+        # if it's not warn that we are defaulting GPU to OpenCL instead.
         gpu_flags=",cuda"
 
         # Unless OpenCL support is specified or we're building on Darwin.

rust/Cargo.lock

@@ -57,6 +57,7 @@ tempfile = "3.0.8"
 default = ["cuda", "multicore-sdr" ]
 blst-portable = ["bls-signatures/blst-portable", "blstrs/portable"]
 cuda = ["filecoin-proofs-api/cuda", "rust-gpu-tools/cuda", "fvm3/cuda", "fvm2/cuda"]
+cuda-supraseal = ["filecoin-proofs-api/cuda-supraseal", "rust-gpu-tools/cuda", "fvm3/cuda-supraseal"]
 opencl = ["filecoin-proofs-api/opencl", "rust-gpu-tools/opencl", "fvm3/opencl", "fvm2/opencl"]
 multicore-sdr = ["filecoin-proofs-api/multicore-sdr"]
 c-headers = ["safer-ffi/headers"]