Hi Lang, clearly your change is not the cause here so please ignore this.

We will investigate what the actual cause of the slowdown was.

Thanks, David Spickett.

On Thu, 28 Oct 2021 at 07:59, ci_notify@linaro.org wrote:

After llvm commit adf55ac6657693f7bfbe3087b599b4031a765a44 Author: Lang Hames lhames@gmail.com

[ORC] Call ExecutorProcessControl::disconnect in unit tests that require it.

the following hot functions slowed down by more than 10% (but their benchmarks slowed down by less than 2%):

• 400.perlbench:[.] S_find_byclass slowed down by 12% from 644 to 721 perf samples

Below reproducer instructions can be used to re-build both "first_bad" and "last_good" cross-toolchains used in this bisection. Naturally, the scripts will fail when triggerring benchmarking jobs if you don't have access to Linaro TCWG CI.

For your convenience, we have uploaded tarballs with pre-processed source and assembly files at:

• First_bad save-temps: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a...
• Last_good save-temps: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a...
• Baseline save-temps: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a...

Configuration:

• Benchmark: SPEC CPU2006
• Toolchain: Clang + Glibc + LLVM Linker
• Version: all components were built from their tip of trunk
• Target: aarch64-linux-gnu
• Compiler flags: -O2
• Hardware: NVidia TX1 4x Cortex-A57

This benchmarking CI is work-in-progress, and we welcome feedback and suggestions at linaro-toolchain@lists.linaro.org . In our improvement plans is to add support for SPEC CPU2017 benchmarks and provide "perf report/annotate" data behind these reports.

THIS IS THE END OF INTERESTING STUFF. BELOW ARE LINKS TO BUILDS, REPRODUCTION INSTRUCTIONS, AND THE RAW COMMIT.

This commit has regressed these CI configurations:

• tcwg_bmk_llvm_tx1/llvm-master-aarch64-spec2k6-O2

First_bad build: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a... Last_good build: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a... Baseline build: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a... Even more details: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a...

Reproduce builds:

<cut> mkdir investigate-llvm-adf55ac6657693f7bfbe3087b599b4031a765a44 cd investigate-llvm-adf55ac6657693f7bfbe3087b599b4031a765a44

# Fetch scripts git clone https://git.linaro.org/toolchain/jenkins-scripts

# Fetch manifests and test.sh script mkdir -p artifacts/manifests curl -o artifacts/manifests/build-baseline.sh https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a... --fail curl -o artifacts/manifests/build-parameters.sh https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a... --fail curl -o artifacts/test.sh https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tx1-llvm-master-a... --fail chmod +x artifacts/test.sh

# Reproduce the baseline build (build all pre-requisites) ./jenkins-scripts/tcwg_bmk-build.sh @@ artifacts/manifests/build-baseline.sh

# Save baseline build state (which is then restored in artifacts/test.sh) mkdir -p ./bisect rsync -a --del --delete-excluded --exclude /bisect/ --exclude /artifacts/ --exclude /llvm/ ./ ./bisect/baseline/

cd llvm

# Reproduce first_bad build git checkout --detach adf55ac6657693f7bfbe3087b599b4031a765a44 ../artifacts/test.sh

# Reproduce last_good build git checkout --detach f526ee5b8517b60620cd03bb3e5945ed69d6bfaa ../artifacts/test.sh

cd ..

</cut>

Full commit (up to 1000 lines):

<cut> commit adf55ac6657693f7bfbe3087b599b4031a765a44 Author: Lang Hames <lhames@gmail.com> Date: Tue Oct 12 14:55:49 2021 -0700

[ORC] Call ExecutorProcessControl::disconnect in unit tests that require it.

Another follow-up to 2815ed57e3c and 19b4e3cfc6a. For unit tests that don't use
an ExecutionSession we need to call ExecutorProcessControl::disconnect directly
to wait for the dispatcher to shut down.

https://llvm.org/PR52153

---

.../ExecutionEngine/Orc/EPCGenericJITLinkMemoryManagerTest.cpp | 2 ++ llvm/unittests/ExecutionEngine/Orc/EPCGenericMemoryAccessTest.cpp | 2 ++ 2 files changed, 4 insertions(+)

diff --git a/llvm/unittests/ExecutionEngine/Orc/EPCGenericJITLinkMemoryManagerTest.cpp b/llvm/unittests/ExecutionEngine/Orc/EPCGenericJITLinkMemoryManagerTest.cpp index f2b157e424b6..a95435aec2a3 100644 --- a/llvm/unittests/ExecutionEngine/Orc/EPCGenericJITLinkMemoryManagerTest.cpp +++ b/llvm/unittests/ExecutionEngine/Orc/EPCGenericJITLinkMemoryManagerTest.cpp @@ -134,6 +134,8 @@ TEST(EPCGenericJITLinkMemoryManagerTest, AllocFinalizeFree) {

auto Err2 = MemMgr->deallocate(std::move(*FA)); EXPECT_THAT_ERROR(std::move(Err2), Succeeded());

• cantFail(SelfEPC->disconnect());

}

} // namespace diff --git a/llvm/unittests/ExecutionEngine/Orc/EPCGenericMemoryAccessTest.cpp b/llvm/unittests/ExecutionEngine/Orc/EPCGenericMemoryAccessTest.cpp index 78024644ca8b..beb0fefa094a 100644 --- a/llvm/unittests/ExecutionEngine/Orc/EPCGenericMemoryAccessTest.cpp +++ b/llvm/unittests/ExecutionEngine/Orc/EPCGenericMemoryAccessTest.cpp @@ -93,6 +93,8 @@ TEST(EPCGenericMemoryAccessTest, MemWrites) { {{pointerToJITTargetAddress(&Test_Buffer), TestMsg}}); EXPECT_THAT_ERROR(std::move(Err5), Succeeded()); EXPECT_EQ(StringRef(Test_Buffer, TestMsg.size()), TestMsg);

• cantFail(SelfEPC->disconnect());

}

} // namespace

</cut>