Messages in this thread | | | From | Andy Lutomirski <> | Date | Sat, 23 Jan 2016 14:09:59 -0800 | Subject | Re: [PATCH 4/5] x86/fpu: Speed up lazy FPU restores slightly |
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On Sat, Jan 23, 2016 at 2:14 AM, Borislav Petkov <bp@alien8.de> wrote: > On Fri, Jan 22, 2016 at 04:56:05PM -0800, Andy Lutomirski wrote: >> If we have an FPU, there's no need to check CR0 for FPU emulation. >> >> Signed-off-by: Andy Lutomirski <luto@kernel.org> >> --- >> arch/x86/kernel/traps.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c >> index 87f80febf477..183b300f6a8b 100644 >> --- a/arch/x86/kernel/traps.c >> +++ b/arch/x86/kernel/traps.c >> @@ -752,7 +752,7 @@ do_device_not_available(struct pt_regs *regs, long error_code) >> RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); >> >> #ifdef CONFIG_MATH_EMULATION >> - if (read_cr0() & X86_CR0_EM) { >> + if (!cpu_has_fpu && (read_cr0() & X86_CR0_EM)) { > > Please use > > boot_cpu_has(X86_FEATURE_FPU) > > We want to kill those cpu_has_xxx things.
Queued for v2.
Maybe this will be just cpu_has some day if my theory about the new improved static_cpu_has being shorter than boot_cpu_has pans out :)
--Andy
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