The microblog: 2018.01.11 22:49:33

2018.01.11 22:49:33 (951571811476623361) from Daniel J. Bernstein, replying to "Murat Ursavaş (@murtikano)" (951557377471516677):

No, anything that's comparing KPTI to non-KPTI is going to obscure the effect I'm wondering about.


2018.01.11 21:23:58 (951550271624241152) from Daniel J. Bernstein:

Even with today's ludicrously bloated kernels, I'm skeptical about the idea that speculative execution _in the kernel_ seriously helps computer performance. Has anyone measured overall slowdown from recompiling kernel branches to use LFENCE with new (fully serializing) microcode?

2018.01.11 21:52:12 (951557377471516677) from "Murat Ursavaş (@murtikano)":

Not sure if this is what you've asked but here's a rough comparison: