On 05/10/2016 02:34, r...@redhat.com wrote:
> From: Andy Lutomirski <l...@kernel.org>
>
> Since commit 58122bf1d856 ("x86/fpu: Default eagerfpu=on on all
> CPUs") in Linux 4.6, eager FPU mode has been the default on all x86
> systems, and no one has reported any regressions.
>
> This patch removes the ability to enable lazy mode: use_eager_fpu()
> becomes "return true" and all of the FPU mode selection machinery is
> removed.
I haven't quite followed up on my promise to benchmark lazy vs. eager
FPU, but I probably should do that now...
I see two possible issues with this. First, AMD as far as I know does
not have XSAVEOPT. Second, when using virtualization, depending on how
you configure your cluster it's enough to have one pre-SandyBridge Intel
machine to force no XSAVE on all machines.
Thanks,
Paolo
