[PATCH] D133153: [support] Prepare TimeProfiler for cross-thread support

[Mark Shields via Phabricator via llvm-commits]

mbs-modular added a comment.

  git switch mbs/time_profiler_warmup
  git rebase 40ab78
  cmake -S llvm -B build -G Ninja -DLLVM_ENABLE_PROJECTS=clang -DLLVM_TARGETS_TO_BUILD=X86 -DCMAKE_BUILD_TYPE=Release -DLLVM_USE_LINKER=lld -DCMAKE_CXX_COMPILER=/usr/bin/clang++ -DCMAKE_C_COMPILER=/usr/bin/clang
  cmake --build build
  touch clang/lib/Sema/SemaExpr.cpp
  cd build
  ninja tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaExpr.cpp.o -v
  
  > /usr/bin/clang++ -DGTEST_HAS_RTTI=0 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/mbs/github/mbs-llvm-project/build/tools/clang/lib/Sema -I/home/mbs/github/mbs-llvm-project/clang/lib/Sema -I/home/mbs/github/mbs-llvm-project/clang/include -I/home/mbs/github/mbs-llvm-project/build/tools/clang/include -I/home/mbs/github/mbs-llvm-project/build/include -I/home/mbs/github/mbs-llvm-project/llvm/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -fno-common -Woverloaded-virtual -Wno-nested-anon-types -O3 -DNDEBUG  -fno-exceptions -fno-rtti -std=c++17 -MD -MT tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaExpr.cpp.o -MF tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaExpr.cpp.o.d -o tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaExpr.cpp.o -c /home/mbs/github/mbs-llvm-project/clang/lib/Sema/SemaExpr.cpp
  
  CLANG="/home/mbs/github/mbs-llvm-project/build/bin/clang++"
  CMD="$CLANG -DGTEST_HAS_RTTI=0 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/mbs/github/mbs-llvm-project/build/tools/clang/lib/Sema -I/home/mbs/github/mbs-llvm-project/clang/lib/Sema -I/home/mbs/github/mbs-llvm-project/clang/include -I/home/mbs/github/mbs-llvm-project/build/tools/clang/include -I/home/mbs/github/mbs-llvm-project/build/include -I/home/mbs/github/mbs-llvm-project/llvm/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -fno-common -Woverloaded-virtual -Wno-nested-anon-types -O3 -DNDEBUG  -fno-exceptions -fno-rtti -std=c++17 -MD -MT tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaExpr.cpp.o -MF tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaExpr.cpp.o.d -o tools/clang/lib/Sema/CMakeFiles/obj.clangSema.dir/SemaExpr.cpp.o -c /home/mbs/github/mbs-llvm-project/clang/lib/Sema/SemaExpr.cpp"
  
  for i in {1..15}; do /usr/bin/time -f "%e" $CMD; done
  
  > 23.93
  23.86
  24.12
  23.84
  23.81
  23.71
  23.74
  23.86
  23.74
  23.74
  23.72
  23.80
  23.65
  23.75
  23.74
  
  
  for i in {1..15}; do /usr/bin/time -f "%e" $CMD -ftime-trace; done
  
  > 25.19
  25.17
  25.08
  25.17
  25.09
  25.18
  24.97
  25.10
  24.93
  24.80
  24.71
  25.04
  25.06
  25.47
  25.38
  
  cd ..
  git switch main
  git checkout 40ab78
  cmake --build build
  cd build
  
  for i in {1..15}; do /usr/bin/time -f "%e" $CMD; done
  
  > 24.11
  23.96
  23.89
  23.88
  23.80
  23.82
  23.90
  23.90
  23.96
  23.83
  23.86
  23.84
  23.92
  23.85
  23.68
  
  for i in {1..15}; do /usr/bin/time -f "%e" $CMD -ftime-trace; done
  
  > 25.18
  25.27
  25.27
  25.25
  25.64
  25.48
  25.12
  25.07
  25.32
  25.14
  25.27
  25.14
  25.30
  25.22
  25.16

Ratio of with flag to without flag is 1.06 both with and without patch.
Ratio of without patch to with path is 1.01 both with and without flag. 
I confirmed I'm indeed using the clang with the changes by emitting error output.
Given the disagreement on your measured times with and without the patch even without the -ftime-trace flag I'm  inclined to write this off to very non-gaussian sampling noise on your setup. wdyt?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D133153/new/

https://reviews.llvm.org/D133153