9c6150b103
Patch adds support for the perf jitdump file specification. With this patch it should be possible to see profile data for code generated and maped at runtime. Specifically the patch adds support for the JIT_CODE_LOAD and the JIT_DEBUG_INFO record as described in the specification. Dumping jitfiles is enabled with the --jitdump flag. When the -g flag is also used there is an attempt to dump file and line number information where this option would be most useful when the WASM file already includes DWARF debug information. The generation of the jitdump files has been tested on only a few wasm files. This patch is expected to be useful/serviceable where currently there is no means for jit profiling, but future patches may benefit line mapping and add support for additional jitdump record types. Usage Example: Record sudo perf record -k 1 -e instructions:u target/debug/wasmtime -g --jitdump test.wasm Combine sudo perf inject -v -j -i perf.data -o perf.jit.data Report sudo perf report -i perf.jit.data -F+period,srcline
Wasmtime: a WebAssembly Runtime
A Bytecode Alliance project
Wasmtime is a standalone wasm-only optimizing runtime for WebAssembly and WASI. It runs WebAssembly code outside of the Web, and can be used both as a command-line utility or as a library embedded in a larger application.
To get started, visit wasmtime.dev.
There are Rust, C, and C++ toolchains that can compile programs with WASI. See the WASI intro for more information, and the WASI tutorial for a tutorial on compiling and running programs using WASI and wasmtime, as well as an overview of the filesystem sandboxing system.
Wasmtime passes the WebAssembly spec testsuite. To run it, update the
tests/spec_testsuite submodule with git submodule update --remote, and it
will be run as part of cargo test.
Wasmtime does not yet implement Spectre mitigations, however this is a subject of ongoing research.
Additional goals for Wasmtime include:
- Support a variety of host APIs (not just WASI), with fast calling sequences, and develop proposals for additional API modules to be part of WASI.
- Facilitate development and testing around the Cranelift and Lightbeam JITs, and other WebAssembly execution strategies.
- Develop a native ABI used for compiling WebAssembly suitable for use in both JIT and AOT to native object files.
Including Wasmtime in your project
Wasmtime exposes an API for embedding as a library through the wasmtime subcrate,
which contains both a high-level and safe Rust API, as well as a C-compatible API
compatible with the proposed WebAssembly C API.
For more information, see the Rust API embedding chapter of the Wasmtime documentation.
It's Wasmtime.