[Bug 242747] geli: AMD Epyc+GELI not using Hardware AES

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=242747

--- Comment #11 from Conrad Meyer <cem at freebsd.org> ---
Yeah, I suspect NCPU threads per disk across 8 disks is not really a great
default!  geli's ncpu default is probably reasonable for single-disk laptops,
but doesn't factor in larger arrays.  threads=2 x 8 disks gets you to 16, or
the number of real cores.  IIRC Epyc has only 128-bit wide vector units
internally, but I don't see how that would affect aesni(4); AES itself is a
128-bit cipher, and the aesni(4) driver only uses SSE intrinsics, which act on
128-bit vectors.  It may simply have fewer vector units and attempting to use
32 of them at the same time contests for shared resources.

-- 
You are receiving this mail because:
You are the assignee for the bug.