Merge pull request #1333 from hodgesds/pgo-builds

build: Add script for pgo/lto builds

Author: hodgesds

pgo-lto.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+set -eou pipefail
+
+PGO_TMPDIR=${1:-/tmp/pgo-data}
+SCHED=${2:-scx_rustland}
+PGO_DUR=${3:-30}
+
+rm -rf "$PGO_TMPDIR"
+mkdir -p "$PGO_TMPDIR"
+
+RUSTFLAGS="-C profile-generate=$PGO_TMPDIR -C link-arg=-lgcov" \
+    cargo build --release --bin "$SCHED"
+
+echo "Running sched to generate PGO"
+for i in {0..3}; do
+	sudo "./target/release/$SCHED" &
+	sleep "$PGO_DUR"
+	sudo kill -9 $! || echo "$SCHED already dead"
+	sleep 1
+done
+
+# Merge the `.profraw` files into a `.profdata` file
+llvm-profdata merge --failure-mode=warn \
+	-o "$PGO_TMPDIR/merged.profdata" \
+	"$PGO_TMPDIR"
+
+# Use the `.profdata` file for guiding optimizations
+RUSTFLAGS="-Cprofile-use=$PGO_TMPDIR/merged.profdata" \
+    cargo build --release --bin "$SCHED"
+