> -----Original Message----- > From: stable-owner@xxxxxxxxxxxxxxx [mailto:stable-owner@xxxxxxxxxxxxxxx] On > Behalf Of 'Greg Kroah-Hartman' > Sent: Friday, June 15, 2018 1:56 PM > To: Daniel Sangorrin <daniel.sangorrin@xxxxxxxxxxxxx> > Cc: linux-kernel@xxxxxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx; 'Andy Lutomirski' > <luto@xxxxxxxxxx>; 'Rik van Riel' <riel@xxxxxxxxxx>; 'Borislav Petkov' > <bp@xxxxxxxxx>; 'Brian Gerst' <brgerst@xxxxxxxxx>; 'Dave Hansen' > <dave.hansen@xxxxxxxxxxxxxxx>; 'Denys Vlasenko' <dvlasenk@xxxxxxxxxx>; > 'Fenghua Yu' <fenghua.yu@xxxxxxxxx>; 'H. Peter Anvin' <hpa@xxxxxxxxx>; 'Josh > Poimboeuf' <jpoimboe@xxxxxxxxxx>; 'Linus Torvalds' > <torvalds@xxxxxxxxxxxxxxxxxxxx>; 'Oleg Nesterov' <oleg@xxxxxxxxxx>; 'Peter > Zijlstra' <peterz@xxxxxxxxxxxxx>; 'Quentin Casasnovas' > <quentin.casasnovas@xxxxxxxxxx>; 'Thomas Gleixner' <tglx@xxxxxxxxxxxxx>; > pbonzini@xxxxxxxxxx; 'Ingo Molnar' <mingo@xxxxxxxxxx> > Subject: Re: [PATCH 4.4 10/24] x86/fpu: Hard-disable lazy FPU mode > > 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. OK, I got it. "x86/fpu: Remove use_eager_fpu()": c592b57347069abfc0dcad3b3a302cf882602597 "x86/fpu: Finish excising 'eagerfpu'": e63650840e8b053aa09ad934877e87e9941ed135 Unfortunately, they don't apply cleanly to stable kernels. Thanks, Daniel Sangorrin
