[Sks-devel] OCaml vs hyperthreading

[Andrew Gallagher]

Since SKS is written in OCaml, this might be of interest to keyserver
operators.

OCaml appears to make (dis?)optimisations that trigger a rare Intel
hyperthreading bug with increased probability. This only happens on
Skylake and Kaby Lake processors. For Skylake (Xeon v5, Core iX-6XXX and
similar), Debian has updated microcode packages available that solve the
issue. For Kaby Lake (Xeon v6, Core iX-7XXX and similar*), the only
foolproof method appears to be to disable hyperthreading and wait for a
vendor patch to drop.

https://lists.debian.org/debian-devel/2017/06/msg00308.html

Andrew.

(*) but some i7-7XXX and i9-7XXX are Skylake; full lists at
https://ark.intel.com/products/codename/37572/Skylake and
https://ark.intel.com/products/codename/82879/Kaby-Lake

[Kristian Fiskerstrand]

Post by Andrew Gallagher
OCaml appears to make (dis?)optimisations that trigger a rare Intel
hyperthreading bug with increased probability.

The way I'm reading it is; When ocaml breaks it is due to a processor
misbehaving :)
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Twitter: @krifisk
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[Kristian Fiskerstrand]

Post by Andrew Gallagher
Since SKS is written in OCaml, this might be of interest to keyserver
operators.

This article might be of interest related to the intel microcode issue:
https://tech.ahrefs.com/skylake-bug-a-detective-story-ab1ad2beddcd
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Blog: https://blog.sumptuouscapital.com
Twitter: @krifisk
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