KPTI is already in kernel 4.14.11, you check if you’re affected via:
cat /proc/cpuinfo | grep cpu_insecure
I’m doing a simple benchmark on my Intel laptop at the moment and will post the results later.
But at least my 80C88 system is unaffected
EDIT: Theo de Raadt of OpenBSD predicted the Meltdown situation over 10 years ago
It might be best for us to move away from x86…
EDIT2: Results from my basic benchmark:
I used kernel 4.14.11 with KPTI enabled and kernel 4.14.10 without KPTI on Laptop with an Intel i3-3110M with 6GB ram
time ./xbps-src -j 4 pkg linux4.13 for both kernels under the same conditions.
4.14.11 with KPTI:
4.14.10 without KTPI:
The performance decrease isn’t too bad for me, but I don’t know how the performance scales with different CPUs, as this is the most powerful Intel chip I own. I’ll have to see if KPTI has any affect on my laptop’s battery life as well.
EDIT3: Red Hat has done some proper performance analysis: https://access.redhat.com/articles/3307751
CPU-intensive workloads are affected the least with only 2-5%
Interesting how close my ‘benchmark’ performance decrease was to what Red Hat are saying.
I wonder if it has a noticeable impact on Void’s build server.
As @pobetiger said, the biggest slowdowns are when there are lots of kernel-to-user space transitions.
Fortunately this probably wont affect the average user too much.