[lkml]   [2020]   [Apr]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [RFC PATCH v2] x86/arch_prctl: Add ARCH_SET_XCR0 to set XCR0 per-thread
> Thank you in advance for any review comments - I thought the comments
> on v1 were quite helpful. I understand this is a tall ask for mainline
> inclusion, but the feature is just too useful for me to give up ;).

> [1]

The rationale from that post should have been in this description.

You can already do what you want using the clearcpuid= boot flags using the
infrastructure in [1], which is in newer kernels.

So to disable AVX512 you would use clearcpuid=304 and the AVX feature
set should be the same as Haswell. To disable AVX2 you would use
clearcpuid=293 and you get the same feature set as Sandy Bridge.

A boot option is not as convenient as a run time setting, but has a lot
less weird corner cases.




 \ /
  Last update: 2020-04-07 16:21    [W:0.083 / U:4.488 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site