4 files changed, 95 insertions, 20 deletions

diff --git a/crates/ra_prof/Cargo.toml b/crates/ra_prof/Cargo.toml
index 6c214501e..e41cb5f52 100644
--- a/crates/ra_prof/Cargo.toml
+++ b/crates/ra_prof/Cargo.toml
@@ -15,6 +15,7 @@ once_cell = "1.3.1"
 backtrace = { version = "0.3.44", optional = true }
 cfg-if = "0.1.10"
 libc = "0.2.73"
+perf-event = "0.4"
 
 [features]
 cpu_profiler = []
diff --git a/crates/ra_prof/src/lib.rs b/crates/ra_prof/src/lib.rs
index ba5609703..eb50965ae 100644
--- a/crates/ra_prof/src/lib.rs
+++ b/crates/ra_prof/src/lib.rs
@@ -1,5 +1,6 @@
 //! A collection of tools for profiling rust-analyzer.
 
+mod stop_watch;
 mod memory_usage;
 #[cfg(feature = "cpu_profiler")]
 mod google_cpu_profiler;
@@ -11,6 +12,7 @@ use std::cell::RefCell;
 pub use crate::{
     hprof::{init, init_from, profile},
     memory_usage::{Bytes, MemoryUsage},
+    stop_watch::{StopWatch, StopWatchSpan},
 };
 
 /// Prints backtrace to stderr, useful for debugging.
diff --git a/crates/ra_prof/src/stop_watch.rs b/crates/ra_prof/src/stop_watch.rs
new file mode 100644
index 000000000..54bfb0559
--- /dev/null
+++ b/crates/ra_prof/src/stop_watch.rs
@@ -0,0 +1,72 @@
+use crate::MemoryUsage;
+use std::{
+    fmt,
+    time::{Duration, Instant},
+};
+
+pub struct StopWatch {
+    time: Instant,
+    counter: Option<perf_event::Counter>,
+    memory: Option<MemoryUsage>,
+}
+
+pub struct StopWatchSpan {
+    pub time: Duration,
+    pub instructions: Option<u64>,
+    pub memory: Option<MemoryUsage>,
+}
+
+impl StopWatch {
+    pub fn start() -> StopWatch {
+        let mut counter = perf_event::Builder::new().build().ok();
+        if let Some(counter) = &mut counter {
+            let _ = counter.enable();
+        }
+        let time = Instant::now();
+        StopWatch { time, counter, memory: None }
+    }
+    pub fn memory(mut self, yes: bool) -> StopWatch {
+        if yes {
+            self.memory = Some(MemoryUsage::current());
+        }
+        self
+    }
+    pub fn elapsed(&mut self) -> StopWatchSpan {
+        let time = self.time.elapsed();
+        let instructions = self.counter.as_mut().and_then(|it| it.read().ok());
+        let memory = self.memory.map(|it| MemoryUsage::current() - it);
+        StopWatchSpan { time, instructions, memory }
+    }
+}
+
+impl fmt::Display for StopWatchSpan {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{:.2?}", self.time)?;
+        if let Some(mut instructions) = self.instructions {
+            let mut prefix = "";
+            if instructions > 10000 {
+                instructions /= 1000;
+                prefix = "k"
+            }
+            if instructions > 10000 {
+                instructions /= 1000;
+                prefix = "m"
+            }
+            write!(f, ", {}{}i", instructions, prefix)?;
+        }
+        if let Some(memory) = self.memory {
+            write!(f, ", {}", memory)?;
+        }
+        Ok(())
+    }
+}
+
+// Unclear if we need this:
+// https://github.com/jimblandy/perf-event/issues/8
+impl Drop for StopWatch {
+    fn drop(&mut self) {
+        if let Some(mut counter) = self.counter.take() {
+            let _ = counter.disable();
+        }
+    }
+}
diff --git a/crates/rust-analyzer/src/cli/analysis_stats.rs b/crates/rust-analyzer/src/cli/analysis_stats.rs
index cf0d82b62..37b8337ef 100644
--- a/crates/rust-analyzer/src/cli/analysis_stats.rs
+++ b/crates/rust-analyzer/src/cli/analysis_stats.rs
@@ -3,7 +3,7 @@
 
 use std::{
     path::Path,
-    time::{Instant, SystemTime, UNIX_EPOCH},
+    time::{SystemTime, UNIX_EPOCH},
 };
 
 use hir::{
@@ -29,6 +29,7 @@ use crate::{
     },
     print_memory_usage,
 };
+use ra_prof::StopWatch;
 
 /// Need to wrap Snapshot to provide `Clone` impl for `map_with`
 struct Snap<DB>(DB);
@@ -54,11 +55,12 @@ pub fn analysis_stats(
         Rand32::new(seed)
     };
 
-    let db_load_time = Instant::now();
+    let mut db_load_sw = StopWatch::start().memory(memory_usage);
     let (host, vfs) = load_cargo(path, load_output_dirs, with_proc_macro)?;
     let db = host.raw_database();
-    eprintln!("Database loaded {:?}", db_load_time.elapsed());
-    let analysis_time = Instant::now();
+    eprintln!("Database loaded {}", db_load_sw.elapsed());
+
+    let mut analysis_sw = StopWatch::start().memory(memory_usage);
     let mut num_crates = 0;
     let mut visited_modules = FxHashSet::default();
     let mut visit_queue = Vec::new();
@@ -110,8 +112,7 @@ pub fn analysis_stats(
     eprintln!("Total modules found: {}", visited_modules.len());
     eprintln!("Total declarations: {}", num_decls);
     eprintln!("Total functions: {}", funcs.len());
-    let item_collection_memory = ra_prof::memory_usage();
-    eprintln!("Item Collection: {:?}, {}", analysis_time.elapsed(), item_collection_memory);
+    eprintln!("Item Collection: {}", analysis_sw.elapsed());
 
     if randomize {
         shuffle(&mut rng, &mut funcs);
@@ -123,7 +124,7 @@ pub fn analysis_stats(
     };
 
     if parallel {
-        let inference_time = Instant::now();
+        let mut inference_sw = StopWatch::start().memory(memory_usage);
         let snap = Snap(db.snapshot());
         funcs
             .par_iter()
@@ -133,14 +134,10 @@ pub fn analysis_stats(
                 snap.0.infer(f_id.into());
             })
             .count();
-        eprintln!(
-            "Parallel Inference: {:?}, {}",
-            inference_time.elapsed(),
-            ra_prof::memory_usage()
-        );
+        eprintln!("Parallel Inference: {}", inference_sw.elapsed());
     }
 
-    let inference_time = Instant::now();
+    let mut inference_sw = StopWatch::start().memory(memory_usage);
     bar.tick();
     let mut num_exprs = 0;
     let mut num_exprs_unknown = 0;
@@ -291,14 +288,17 @@ pub fn analysis_stats(
     eprintln!("Type mismatches: {}", num_type_mismatches);
     report_metric("type mismatches", num_type_mismatches, "#");
 
-    let inference_time = inference_time.elapsed();
-    let total_memory = ra_prof::memory_usage();
-    eprintln!("Inference: {:?}, {}", inference_time, total_memory - item_collection_memory);
+    eprintln!("Inference: {}", inference_sw.elapsed());
 
-    let analysis_time = analysis_time.elapsed();
-    eprintln!("Total: {:?}, {}", analysis_time, total_memory);
-    report_metric("total time", analysis_time.as_millis() as u64, "ms");
-    report_metric("total memory", total_memory.allocated.megabytes() as u64, "MB");
+    let total_span = analysis_sw.elapsed();
+    eprintln!("Total: {}", total_span);
+    report_metric("total time", total_span.time.as_millis() as u64, "ms");
+    if let Some(instructions) = total_span.instructions {
+        report_metric("total time", instructions, "#instr");
+    }
+    if let Some(memory) = total_span.memory {
+        report_metric("total memory", memory.allocated.megabytes() as u64, "MB");
+    }
 
     if memory_usage {
         print_memory_usage(host, vfs);