Benchmarks after Meltdown, Spectre and CPU Microcode Updates

[Jeffrey Walton]

Hi Everyone,

I've been benchmarking since Meltdown and Spectre updates were released. The updates include kernel updates, EFI updates and CPU microcode updates.

I don't see a difference based on the benchmarks of the algorithms the library provides. This makes sense since the isolation fixes should affect the userland/kernel task switch. The benchmarks don't really make system calls to incur a penalty. Some system calls are made, but there are not too many of them.

For example, here is SHA on a Celeron J3455 (Goldmont ISA), which supplies SHA extensions. Both achieve about 1.2 GiB/s for SHA1, and both achieve about 535 MiB/s for SHA-256.

  - Before patches

        <TR><TD>SHA-1<TD>1192<TD>1.68
        <TR><TD>SHA-256<TD>537<TD>3.73

  - After patches

        <TR><TD>SHA-1<TD>1193<TD>1.68
        <TR><TD>SHA-256<TD>536<TD>3.74

Jeff