Linux 5.5 Regression Bisected On AMD EPYC Rome

Tests for a future article.

HTML result view exported from: https://openbenchmarking.org/result/1912290-HU-LINUX55HA55.

Linux 5.5 Regression Bisected On AMD EPYC RomeProcessorMotherboardChipsetMemoryDiskGraphicsMonitorNetworkOSKernelDesktopDisplay ServerDisplay DriverCompilerFile-SystemScreen Resolution5.5.0-rc3-ptsv5.48c39f71ee201937d6eefc716eb275167d18648d6b4dd362c2352923c753f4672c2f2026d01d1dff64662aef069a277dc8321c2ecb2e8341c1fda5e17bf1d2ee7bc6200e0590dbaec8f21a6247525bce4e7e9c45eapparmor=02 x AMD EPYC 7742 64-Core @ 2.25GHz (128 Cores / 256 Threads)AMD DAYTONA_X (RDY1001C BIOS)AMD Starship/Matisse516096MB280GB INTEL SSDPE21D280GA + 256GB Micron_1100_MTFDASPEEDVE2282 x Mellanox MT27710Ubuntu 19.105.5.0-rc3-pts (x86_64) 20191229GNOME Shell 3.34.1X Server 1.20.5modesetting 1.20.5GCC 9.2.1 20191008 + LLVM 9.0.0ext41920x10805.4.0-pts (x86_64)5.4.0-rc1-pts (x86_64) 201912295.1.0-rc4-pts (x86_64) 201912295.5.0-rc3-pts (x86_64) 20191229OpenBenchmarking.orgCompiler Details- --build=x86_64-linux-gnu --disable-vtable-verify --disable-werror --enable-bootstrap --enable-checking=release --enable-clocale=gnu --enable-default-pie --enable-gnu-unique-object --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,gm2 --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-multiarch --enable-multilib --enable-nls --enable-offload-targets=nvptx-none,hsa --enable-plugin --enable-shared --enable-threads=posix --host=x86_64-linux-gnu --program-prefix=x86_64-linux-gnu- --target=x86_64-linux-gnu --with-abi=m64 --with-arch-32=i686 --with-default-libstdcxx-abi=new --with-gcc-major-version-only --with-multilib-list=m32,m64,mx32 --with-target-system-zlib=auto --with-tune=generic --without-cuda-driver -v Processor Details- Scaling Governor: acpi-cpufreq ondemand - CPU Microcode: 0x830101cPython Details- 5.5.0-rc3-pts, v5.4, 8c39f71ee201, 937d6eefc716, eb275167d186: Python 2.7.17 + Python 3.7.5Security Details- 5.5.0-rc3-pts: itlb_multihit: Not affected + l1tf: Not affected + mds: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of usercopy/swapgs barriers and __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling + tsx_async_abort: Not affected- v5.4: itlb_multihit: Not affected + l1tf: Not affected + mds: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of usercopy/swapgs barriers and __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling + tsx_async_abort: Not affected- 8c39f71ee201: itlb_multihit: Not affected + l1tf: Not affected + mds: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of usercopy/swapgs barriers and __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling + tsx_async_abort: Not affected- 937d6eefc716: itlb_multihit: Not affected + l1tf: Not affected + mds: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of usercopy/swapgs barriers and __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling + tsx_async_abort: Not affected- eb275167d186: itlb_multihit: Not affected + l1tf: Not affected + mds: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of usercopy/swapgs barriers and __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling + tsx_async_abort: Not affected- 48d6b4dd362c: itlb_multihit: Not affected + l1tf: Not affected + mds: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of usercopy/swapgs barriers and __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling + tsx_async_abort: Not affected- 2352923c753f: itlb_multihit: Not affected + l1tf: Not affected + mds: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of usercopy/swapgs barriers and __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling + tsx_async_abort: Not affected- 4672c2f2026d: itlb_multihit: Not affected + l1tf: Not affected + mds: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of usercopy/swapgs barriers and __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling + tsx_async_abort: Not affected- 01d1dff64662: itlb_multihit: Not affected + l1tf: Not affected + mds: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of usercopy/swapgs barriers and __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling + tsx_async_abort: Not affected- aef069a277dc: l1tf: Not affected + mds: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of usercopy/swapgs barriers and __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling- 8321c2ecb2e8: l1tf: Not affected + mds: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of usercopy/swapgs barriers and __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling- 341c1fda5e17: l1tf: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling- bf1d2ee7bc62: l1tf: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling- 00e0590dbaec: l1tf: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling- 8f21a6247525: l1tf: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling- bce4e7e9c45e: l1tf: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling- apparmor=0: itlb_multihit: Not affected + l1tf: Not affected + mds: Not affected + meltdown: Not affected + spec_store_bypass: Mitigation of SSB disabled via prctl and seccomp + spectre_v1: Mitigation of usercopy/swapgs barriers and __user pointer sanitization + spectre_v2: Mitigation of Full AMD retpoline IBPB: conditional IBRS_FW STIBP: conditional RSB filling + tsx_async_abort: Not affected

Linux 5.5 Regression Bisected On AMD EPYC Romehackbench: 32 - ProcessDifferenceStandard ErrorStandard Deviation5.5.0-rc3-ptsv5.48c39f71ee201937d6eefc716eb275167d18648d6b4dd362c2352923c753f4672c2f2026d01d1dff64662aef069a277dc8321c2ecb2e8341c1fda5e17bf1d2ee7bc6200e0590dbaec8f21a6247525bce4e7e9c45eapparmor=049.2231.20x0.200.70%15.2811.75x0.121.36%12.5861.80x0.152.71%12.4971.80x0.202.76%49.5771.20x0.210.73%49.4991.20x0.210.75%12.3541.80x0.192.60%49.8061.19x0.230.79%12.5361.80x0.122.92%14.9511.76x0.080.93%15.5011.75x0.111.28%61.6281.00x0.411.16%13.9111.77x0.050.62%14.2731.77x0.050.56%13.9591.77x0.151.80%47.7851.22x0.311.13%12.2671.80x0.152.90%OpenBenchmarking.org

Hackbench

Count: 32 - Type: Process

OpenBenchmarking.orgSeconds, Fewer Is BetterHackbenchCount: 32 - Type: Process5.5.0-rc3-ptsv5.48c39f71ee201937d6eefc716eb275167d18648d6b4dd362c2352923c753f4672c2f2026d01d1dff64662aef069a277dc8321c2ecb2e8341c1fda5e17bf1d2ee7bc6200e0590dbaec8f21a6247525bce4e7e9c45eapparmor=01428425670SE +/- 0.20, N = 3SE +/- 0.12, N = 3SE +/- 0.15, N = 5SE +/- 0.20, N = 3SE +/- 0.21, N = 3SE +/- 0.21, N = 3SE +/- 0.19, N = 3SE +/- 0.23, N = 3SE +/- 0.12, N = 9SE +/- 0.08, N = 3SE +/- 0.11, N = 3SE +/- 0.41, N = 3SE +/- 0.05, N = 3SE +/- 0.05, N = 3SE +/- 0.15, N = 3SE +/- 0.31, N = 3SE +/- 0.15, N = 649.2215.2812.5912.5049.5849.5012.3549.8112.5414.9515.5061.6313.9114.2713.9647.7912.271. (CC) gcc options: -lpthread

Phoronix Test Suite v10.8.4