From 87e97c9035273acf187b5a4eab5a32b8ccebe13b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jakub=20Ber=C3=A1nek?= Date: Wed, 18 May 2022 10:48:47 +0200 Subject: [PATCH] Add PID to LLVM PGO profiles generated in CI and measure PGO statistics --- src/bootstrap/native.rs | 3 +++ src/ci/pgo.sh | 46 ++++++++++++++++++++++++++++++++--------- 2 files changed, 39 insertions(+), 10 deletions(-) diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs index 09b8cbe9014..f57fb160d18 100644 --- a/src/bootstrap/native.rs +++ b/src/bootstrap/native.rs @@ -503,6 +503,9 @@ fn run(self, builder: &Builder<'_>) -> PathBuf { if builder.config.llvm_profile_generate { cfg.define("LLVM_BUILD_INSTRUMENTED", "IR"); + if let Ok(llvm_profile_dir) = std::env::var("LLVM_PROFILE_DIR") { + cfg.define("LLVM_PROFILE_DATA_DIR", llvm_profile_dir); + } cfg.define("LLVM_BUILD_RUNTIME", "No"); } if let Some(path) = builder.config.llvm_profile_use.as_ref() { diff --git a/src/ci/pgo.sh b/src/ci/pgo.sh index 9b727947f6a..9de970c9c2a 100755 --- a/src/ci/pgo.sh +++ b/src/ci/pgo.sh @@ -39,12 +39,19 @@ gather_profiles () { rm -rf /tmp/rustc-pgo +# This path has to be absolute +LLVM_PROFILE_DIRECTORY_ROOT=/tmp/llvm-pgo + # We collect LLVM profiling information and rustc profiling information in # separate phases. This increases build time -- though not by a huge amount -- # but prevents any problems from arising due to different profiling runtimes # being simultaneously linked in. - -python3 ../x.py build --target=$PGO_HOST --host=$PGO_HOST \ +# LLVM IR PGO does not respect LLVM_PROFILE_FILE, so we have to set the profiling file +# path through our custom environment variable. We include the PID in the directory path +# to avoid updates to profile files being lost because of race conditions. +LLVM_PROFILE_DIR=${LLVM_PROFILE_DIRECTORY_ROOT}/prof-%p python3 ../x.py build \ + --target=$PGO_HOST \ + --host=$PGO_HOST \ --stage 2 library/std \ --llvm-profile-generate @@ -64,11 +71,18 @@ RUSTC_BOOTSTRAP=1 \ gather_profiles "Debug,Opt" "Full" \ "syn-1.0.89,cargo-0.60.0,serde-1.0.136,ripgrep-13.0.0,regex-1.5.5,clap-3.1.6,hyper-0.14.18" +LLVM_PROFILE_MERGED_FILE=/tmp/llvm-pgo.profdata + # Merge the profile data we gathered for LLVM # Note that this uses the profdata from the clang we used to build LLVM, # which likely has a different version than our in-tree clang. -/rustroot/bin/llvm-profdata \ - merge -o /tmp/llvm-pgo.profdata ./build/$PGO_HOST/llvm/build/profiles +/rustroot/bin/llvm-profdata merge -o ${LLVM_PROFILE_MERGED_FILE} ${LLVM_PROFILE_DIRECTORY_ROOT} + +echo "LLVM PGO statistics" +du -sh ${LLVM_PROFILE_MERGED_FILE} +du -sh ${LLVM_PROFILE_DIRECTORY_ROOT} +echo "Profile file count" +find ${LLVM_PROFILE_DIRECTORY_ROOT} -type f | wc -l # Rustbuild currently doesn't support rebuilding LLVM when PGO options # change (or any other llvm-related options); so just clear out the relevant @@ -77,9 +91,12 @@ rm -r ./build/$PGO_HOST/llvm ./build/$PGO_HOST/lld # Okay, LLVM profiling is done, switch to rustc PGO. +# The path has to be absolute +RUSTC_PROFILE_DIRECTORY_ROOT=/tmp/rustc-pgo + python3 ../x.py build --target=$PGO_HOST --host=$PGO_HOST \ --stage 2 library/std \ - --rust-profile-generate=/tmp/rustc-pgo + --rust-profile-generate=${RUSTC_PROFILE_DIRECTORY_ROOT} # Here we're profiling the `rustc` frontend, so we also include `Check`. # The benchmark set includes various stress tests that put the frontend under pressure. @@ -87,12 +104,21 @@ python3 ../x.py build --target=$PGO_HOST --host=$PGO_HOST \ # rustc invocation ends. Empirically, this can result in some profiling data being lost. # That's why we override the profile path to include the PID. This will produce many more profiling # files, but the resulting profile will produce a slightly faster rustc binary. -LLVM_PROFILE_FILE=/tmp/rustc-pgo/default_%m_%p.profraw gather_profiles "Check,Debug,Opt" "All" \ -"externs,ctfe-stress-5,cargo-0.60.0,token-stream-stress,match-stress,tuple-stress,diesel-1.4.8,bitmaps-3.1.0" +LLVM_PROFILE_FILE=${RUSTC_PROFILE_DIRECTORY_ROOT}/default_%m_%p.profraw gather_profiles \ + "Check,Debug,Opt" "All" \ + "externs,ctfe-stress-5,cargo-0.60.0,token-stream-stress,match-stress,tuple-stress,diesel-1.4.8,bitmaps-3.1.0" + +RUSTC_PROFILE_MERGED_FILE=/tmp/rustc-pgo.profdata # Merge the profile data we gathered ./build/$PGO_HOST/llvm/bin/llvm-profdata \ - merge -o /tmp/rustc-pgo.profdata /tmp/rustc-pgo + merge -o ${RUSTC_PROFILE_MERGED_FILE} ${RUSTC_PROFILE_DIRECTORY_ROOT} + +echo "Rustc PGO statistics" +du -sh ${RUSTC_PROFILE_MERGED_FILE} +du -sh ${RUSTC_PROFILE_DIRECTORY_ROOT} +echo "Profile file count" +find ${RUSTC_PROFILE_DIRECTORY_ROOT} -type f | wc -l # Rustbuild currently doesn't support rebuilding LLVM when PGO options # change (or any other llvm-related options); so just clear out the relevant @@ -102,5 +128,5 @@ rm -r ./build/$PGO_HOST/llvm ./build/$PGO_HOST/lld # This produces the actual final set of artifacts, using both the LLVM and rustc # collected profiling data. $@ \ - --rust-profile-use=/tmp/rustc-pgo.profdata \ - --llvm-profile-use=/tmp/llvm-pgo.profdata + --rust-profile-use=${RUSTC_PROFILE_MERGED_FILE} \ + --llvm-profile-use=${LLVM_PROFILE_MERGED_FILE}