# Spectre v2 and Meltdown mitigations for 11.1



## Eric A. Borisch (Mar 14, 2018)

Available: https://www.freebsd.org/security/advisories/FreeBSD-SA-18:03.speculative_execution.asc


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## obsigna (Mar 14, 2018)

I just updated my development machine running a daemon wich permanently reads and evaluates a measurement data stream (from a NI DAQ card) at a high rate. Before the update, the CPU utilization as reported by top(1) was 9.1 % and after the update it was 10.1 %. This makes up for a performance penalty of 10 %. When I disable the new PTI mechanism by adding vm.pmap.pti=0 to /boot/loader.conf, the CPU utilization is still slightly above the previous value, now 9.4 %.

Anyway, I am in favor of the PTI because it would have been the right thing to do already long time ago. I hope that future processors com with PTI hardware units in addition to fixing the speculative execution schemes.

I cannot talk about the Spectre V2 mitigation, because for this processor there is still no microcode update available.


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