glibc TUNABLES

glibc 提供了一些开关来调优 https://www.gnu.org/software/libc/manual/html_node/Tunables.html
例如我们在AVX机器上测试不开启SIMD memcpy的性能。

export GLIBC_TUNABLES=glibc.cpu.hwcaps=-CX8,-CMOV,-SSE,-SSE2,-SSSE3,-SSE4_1,-SSE4_2,-AVX,-AVX2,-AVX512F,-AVX512DQ,-AVX512PF,-AVX512ER,-AVX512CD,-AVX512BW,-AVX512VL,-ERMS,-RTM,-FMA,-FMA4,-POPCOUNT,-OSXSAVE,-HTT,-BMI1,-BMI2,-LZCNT,-MOVBE,-POPCNT,-IBT,-SHSTK

查看是否生效:

 /lib64/ld-linux-x86-64.so.2    --list-tunables