Re: [RFC 1/6]SEP initialization rework

[Li Shaohua <shaohua.li@intel.com>]

On Tue, 2005-04-05 at 03:10, Zwane Mwaikambo wrote:
> On Mon, 4 Apr 2005, Li Shaohua wrote:
> 
> >  linux-2.6.11-root/arch/i386/kernel/smpboot.c           |    6 ++++++
> >  linux-2.6.11-root/arch/i386/kernel/sysenter.c          |   10 ++++++----
> >  linux-2.6.11-root/arch/i386/mach-voyager/voyager_smp.c |    6 ++++++
> >  3 files changed, 18 insertions(+), 4 deletions(-)
> > 
> > diff -puN arch/i386/kernel/sysenter.c~sep_init_cleanup arch/i386/kernel/sysenter.c
> > --- linux-2.6.11/arch/i386/kernel/sysenter.c~sep_init_cleanup	2005-03-28 09:32:30.936304248 +0800
> > +++ linux-2.6.11-root/arch/i386/kernel/sysenter.c	2005-03-28 09:58:20.703703792 +0800
> > @@ -26,6 +26,11 @@ void enable_sep_cpu(void *info)
> >  	int cpu = get_cpu();
> >  	struct tss_struct *tss = &per_cpu(init_tss, cpu);
> >  
> > +	if (!boot_cpu_has(X86_FEATURE_SEP)) {
> > +		put_cpu();
> > +		return;
> > +	}
> > +
> 
> Do you have systems like this? Is it really skipping SEP if the boot 
> processor doesn't have SEP?
No, I haven't such system. This is the logic of original SEP
initialization. If the CPU hasn't SEP, original logic doesn't call
'on_each_cpu(enable_sep_cpu,...)'.

Thanks,
Shaohua