Re: [PATCH v6] x86: load FPU registers on return to userland

Borislav Petkov
2019-01-30T11:36:07Z

On Wed, Jan 09, 2019 at 12:47:22PM +0100, Sebastian Andrzej Siewior wrote:
> This is a refurbished series originally started by by Rik van Riel. The
> goal is load the FPU registers on return to userland and not on every
> context switch. By this optimisation we can:
> - avoid loading the registers if the task stays in kernel and does
> not return to userland
> - make kernel_fpu_begin() cheaper: it only saves the registers on the
> first invocation. The second invocation does not need save them again.

Btw, do we have any benchmark data showing the improvement this brings?

--
Regards/Gruss,
Boris.

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