Re: [PATCH 4.4 10/24] x86/fpu: Hard-disable lazy FPU mode

From: 'Greg Kroah-Hartman'
Date: Fri Jun 15 2018 - 00:56:45 EST


On Fri, Jun 15, 2018 at 01:24:27PM +0900, Daniel Sangorrin wrote:
> Hi Greg,
>
> > /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
> > --- a/arch/x86/include/asm/fpu/internal.h
> > +++ b/arch/x86/include/asm/fpu/internal.h
> > @@ -58,7 +58,7 @@ extern u64 fpu__get_supported_xfeatures_
> > */
> > static __always_inline __pure bool use_eager_fpu(void)
> > {
> > - return static_cpu_has_safe(X86_FEATURE_EAGER_FPU);
> > + return true;
> > }
>
> Since this function returns always true then we can remove the code depending on lazy FPU mode.
> Actually this has already been done in "x86/fpu: Remove use_eager_fpu()"
> Ref: https://patchwork.kernel.org/patch/9365883/
>
> > static void __init fpu__init_parse_early_param(void)
> > {
> > - if (cmdline_find_option_bool(boot_command_line, "eagerfpu=off")) {
> > - eagerfpu = DISABLE;
> > - fpu__clear_eager_fpu_features();
> > - }
>
> Since this patch removes the kernel boot parameter "eagerfpu", maybe we should remove it from the Documentation.
> This has also been done by commit "x86/fpu: Finish excising 'eagerfpu'"
> Ref: https://patchwork.kernel.org/patch/9380673/
>
> I will try backporting those patches unless anyone has any objections.

What are the git commit ids of those patches in Linus's tree? No need
to point to patchwork links, I don't use that tool.

thanks,

greg k-h