wasmtime / issue #6923 VTune support for C-API doesn't work · git-wasmtime

Test Case

Modified examples/gcd.c to utilize C-API as directed here

int main() {
  int ret = 0;
  // Set up our context
  //wasm_engine_new();
  wasm_config_t* wasmtime_configuration = wasm_config_new();
  wasmtime_config_profiler_set(wasmtime_configuration, WASMTIME_PROFILING_STRATEGY_VTUNE);
  wasm_engine_t *engine = wasm_engine_new_with_config(wasmtime_configuration);
  assert(engine != NULL);
  wasmtime_store_t *store = wasmtime_store_new(engine, NULL, NULL);
  assert(store != NULL);
  wasmtime_context_t *context = wasmtime_store_context(store);

Steps to Reproduce

Add VTune feature to c-api crate's Cargo.toml wasmtime/crates/c-api/Cargo.toml :

[features]
.
.
.
vtune = ["wasmtime/vtune"]

Build wasmtime-c-api cargo build --release -p wasmtime-c-api --features vtune

Build gcd binary :

cc examples/gcd.c \
       -I crates/c-api/include \
       -I crates/c-api/wasm-c-api/include \
       target/release/libwasmtime.a \
       -lpthread -ldl -lm \
       -o gcd

Now, run the binary by launching it with VTune, from command line it like below -
vtune -collect hotspots -knob sampling-mode=hw -r out_dir ./gcd

Expected Results

VTune runs to completion with no errors from gcd binary, and then VTune shows [Dynamic Code] module with wasm functions inside it.

Actual Results

GCD binary does not run to completion. Normal execution time is a few seconds (I had loops inside of the original gcd.c, tested without vtune hooks) , this one crashes in a second or so with following output from VTune, with data file corrupted.

vtune -collect hotspots -knob sampling-mode=hw -r vtune-gcd-hardcoded2 ./gcd-mod
vtune: Warning: To enable hardware event-based sampling, VTune Profiler has disabled the NMI watchdog timer. The watchdog timer will be re-enabled after collection completes.
vtune: Collection started. To stop the collection, either press CTRL-C or enter from another console window: vtune -r /home/oem/public_repos/wasmtime/vtune-gcd-hardcoded2 -command stop.
vtune: Collection stopped.
vtune: Using result path `/home/oem/public_repos/wasmtime/vtune-gcd-hardcoded2'
vtune: Executing actions 12 % Loading 'userapicollector-2992789-09cf7a40.trace'
vtune: Error: Cannot load data file `/home/oem/public_repos/wasmtime/vtune-gcd-hardcoded2/data.0/userapicollector-2992789-09cf7a40.trace' (Data file is corrupted).
vtune: Executing actions 19 % Resolving information for `libittnotify_collector

Versions and Environment

Wasmtime version or commit: Main branch, commit 8efcb9851602287fd07a1a1e91501f51f2653d7e

Operating system: Ubuntu

Architecture: x86

Extra Info

The above failure actually does produce .JIT file in VTune directory.
When no VTune collection is ongoing, and you simply run ./gcd, we get the following error

 RUST_BACKTRACE=FULL ./gcd
thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: error when notifying event', crates/jit/src/profiling/vtune.rs:57:14
stack backtrace:
   0: rust_begin_unwind
             at /rustc/eb26296b556cef10fb713a38f3d16b9886080f26/library/std/src/panicking.rs:593:5
   1: core::panicking::panic_fmt
             at /rustc/eb26296b556cef10fb713a38f3d16b9886080f26/library/core/src/panicking.rs:67:14
   2: core::result::unwrap_failed
             at /rustc/eb26296b556cef10fb713a38f3d16b9886080f26/library/core/src/result.rs:1651:5
   3: core::result::Result<T,E>::unwrap
             at /rustc/eb26296b556cef10fb713a38f3d16b9886080f26/library/core/src/result.rs:1076:23
   4: wasmtime_jit::profiling::vtune::State::notify_code
             at ./crates/jit/src/profiling/vtune.rs:51:9
   5: wasmtime_jit::profiling::vtune::State::register_function
             at ./crates/jit/src/profiling/vtune.rs:78:9
   6: <wasmtime_jit::profiling::vtune::VTuneAgent as wasmtime_jit::profiling::ProfilingAgent>::register_function
             at ./crates/jit/src/profiling/vtune.rs:69:9
   7: wasmtime_jit::profiling::ProfilingAgent::register_module
             at ./crates/jit/src/profiling.rs:92:17
   8: wasmtime_jit::instantiate::CompiledModule::register_debug_and_profiling
             at ./crates/jit/src/instantiate.rs:481:9
   9: wasmtime_jit::instantiate::CompiledModule::from_artifacts
             at ./crates/jit/src/instantiate.rs:468:9
  10: wasmtime::module::Module::from_parts_raw
             at ./crates/wasmtime/src/module.rs:577:22
  11: wasmtime::module::Module::from_parts
             at ./crates/wasmtime/src/module.rs:568:9
  12: wasmtime::module::Module::from_binary
             at ./crates/wasmtime/src/module.rs:333:16
  13: wasmtime_module_new
             at ./crates/c-api/src/module.rs:140:9
  14: main
             at ./examples/gcd.c:70:11

  15: __libc_start_main
             at /build/glibc-SzIz7B/glibc-2.31/csu/../csu/libc-start.c:308:16
  16: _start
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
fatal runtime error: failed to initiate panic, error 5
Aborted (core dumped)

Looks somewhat similar to what @abrown reported for CLI https://github.com/bytecodealliance/wasmtime/issues/5628

Stream: git-wasmtime

Topic: wasmtime / issue #6923 VTune support for C-API doesn't work