Linux KPTI performance hit on real workloads
There have been a lot of people quoting figures about the #Meltdown and #spectre issues on the internet. At cyberstorm.mu, we decided to benchmark the latest patches in Linux kernel 4.11, on Void Linux. We use VoidLinux to avoid relying on systemd :)
Our spec machine:
CPU: Intel(R) Core(TM) i5–4460 CPU @ 3.20GHz (Haswell)
VoidLinux 4.14.11_1 #1 SMP PREEMPT Wed Jan 3 16:59:01 UTC 2018 x86_64 GNU/Linux
RAM: 32GB RAM
SSD: Samsung Evo 850 250GB
compiling linux kernel using make -j8.
Time taken:
real 30m59.314s
user 106m11.840s
sys 10m51.330s
Now with Linux kernel 4.11.8.
Kernel compilation:
real 29m13.027s
user 103m42.483s
sys 9m49.468s
Conclusion:
For kernel compilation, we are hitting a performance penalty of : 5%, with KPTI on my Intel haswell CPU.
[Feel free to submit difference ideas for benchmarking on Linux in the comments section]