Messages in this thread | | | From | David Laight <> | Subject | RE: [RFC PATCH v2 1/2] x86/fpu: detect AVX task | Date | Tue, 13 Nov 2018 10:25:54 +0000 |
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From: Li, Aubrey > Sent: 12 November 2018 01:41 ... > VZEROUPPER instruction resets the init state. If context switch happens > to occur exactly after VZEROUPPER instruction, XINUSE bitmap is empty(all > zeros), which indicates the task is not using AVX. That's why the state > decay count is used here.
Isn't there an obvious optimisation to execute VZEROALL during system call entry? If that is done does any of this actually work?
David
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