Integrate measureme's hardware performance counter support.

Author: eddyb

compiler/rustc_data_structures/src/profiling.rs

@@ -550,14 +550,20 @@ impl SelfProfiler {
     pub fn new(
         output_directory: &Path,
         crate_name: Option<&str>,
-        event_filters: &Option<Vec<String>>,
+        event_filters: Option<&[String]>,
+        counter_name: &str,
     ) -> Result<SelfProfiler, Box<dyn Error + Send + Sync>> {
         fs::create_dir_all(output_directory)?;
 
         let crate_name = crate_name.unwrap_or("unknown-crate");
-        let filename = format!("{}-{}.rustc_profile", crate_name, process::id());
+        // HACK(eddyb) we need to pad the PID, strange as it may seem, as its
+        // length can behave as a source of entropy for heap addresses, when
+        // ASLR is disabled and the heap is otherwise determinic.
+        let pid: u32 = process::id();
+        let filename = format!("{}-{:07}.rustc_profile", crate_name, pid);
         let path = output_directory.join(&filename);
-        let profiler = Profiler::new(&path)?;
+        let profiler =
+            Profiler::with_counter(&path, measureme::counters::Counter::by_name(counter_name)?)?;
 
         let query_event_kind = profiler.alloc_string("Query");
         let generic_activity_event_kind = profiler.alloc_string("GenericActivity");
@@ -570,7 +576,7 @@ impl SelfProfiler {
 
         let mut event_filter_mask = EventFilter::empty();
 
-        if let Some(ref event_filters) = *event_filters {
+        if let Some(event_filters) = event_filters {
             let mut unknown_events = vec![];
             for item in event_filters {
                 if let Some(&(_, mask)) =

compiler/rustc_query_impl/src/profiling_support.rs

@@ -275,6 +275,9 @@ fn alloc_self_profile_query_strings_for_query_cache<'tcx, C>(
             let query_name = profiler.get_or_alloc_cached_string(query_name);
             let event_id = event_id_builder.from_label(query_name).to_string_id();
 
+            // FIXME(eddyb) make this O(1) by using a pre-cached query name `EventId`,
+            // instead of passing the `DepNodeIndex` to `finish_with_query_invocation_id`,
+            // when recording the event in the first place.
             let mut query_invocation_ids = Vec::new();
             query_cache.iter(&mut |_, _, i| {
                 query_invocation_ids.push(i.into());

compiler/rustc_session/src/options.rs

@@ -1473,6 +1473,12 @@ options! {
         for example: `-Z self-profile-events=default,query-keys`
         all options: none, all, default, generic-activity, query-provider, query-cache-hit
                      query-blocked, incr-cache-load, incr-result-hashing, query-keys, function-args, args, llvm, artifact-sizes"),
+    self_profile_counter: String = ("wall-time".to_string(), parse_string, [UNTRACKED],
+        "counter used by the self profiler (default: `wall-time`), one of:
+        `wall-time` (monotonic clock, i.e. `std::time::Instant`)
+        `instructions:u` (retired instructions, userspace-only)
+        `instructions-minus-irqs:u` (subtracting hardware interrupt counts for extra accuracy)"
+    ),
     share_generics: Option<bool> = (None, parse_opt_bool, [TRACKED],
         "make the current crate share its generic instantiations"),
     show_span: Option<String> = (None, parse_opt_string, [TRACKED],

compiler/rustc_session/src/session.rs

@@ -1252,7 +1252,8 @@ pub fn build_session(
         let profiler = SelfProfiler::new(
             directory,
             sopts.crate_name.as_deref(),
-            &sopts.debugging_opts.self_profile_events,
+            sopts.debugging_opts.self_profile_events.as_ref().map(|xs| &xs[..]),
+            &sopts.debugging_opts.self_profile_counter,
         );
         match profiler {
             Ok(profiler) => Some(Arc::new(profiler)),