lkml.org 
[lkml]   [2009]   [Apr]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [git-pull -tip] x86: cpu_debug patches
From
Date
On Wed, 2009-04-29 at 12:50 +0200, Ingo Molnar wrote:
> * Jaswinder Singh Rajput <jaswinder@kernel.org> wrote:
>
> > On Tue, 2009-04-28 at 19:28 +0200, Ingo Molnar wrote:
> > > * Jaswinder Singh Rajput <jaswinder@kernel.org> wrote:
> > >
> > > > @@ -850,10 +903,10 @@ static int cpu_init_cpu(void)
> > > > cpui = &cpu_data(cpu);
> > > > if (!cpu_has(cpui, X86_FEATURE_MSR))
> > > > continue;
> > > > - per_cpu(cpu_model, cpu) = ((cpui->x86_vendor << 16) |
> > > > - (cpui->x86 << 8) |
> > > > - (cpui->x86_model));
> > > > - per_cpu(cpu_modelflag, cpu) = get_cpu_modelflag(cpu);
> > > > + per_cpu(cpu_modelflag, cpu) = get_cpu_flag(cpui);
> > > > + if (!per_cpu(cpu_modelflag, cpu))
> > > > + send_report(per_cpu(cpu_priv_count, cpu), cpui);
> > >
> > > This means that if the CPU is not enumerated in the model table
> > > explicitly, we'll fall back to some really minimal output, right?
> > >
> >
> > Yes.
>
> That's a bug really: it means that for every new CPU type that comes
> around we need to update this code. I.e. precisely for those CPUs
> where we might need the most help from such a debug facility, we
> wont have much info to look at ... New CPUs generally support all
> the CPU features that are displayed here, in a compatible manner.
>
> So that needs to be improved/changed to not be tied to such a static
> 'cpu model' enumeration but instead be CPU feature flags driven. See
> all the existing cpu_has_*() tests we have.
>

cpu_has_*() is based on boot_cpu. So you mean cpu_has tests. right ?

We can use cpu_has tests for unknown processors but 'cpu model' is
accurate and cover all range.

cpu_has does not cover following registers:
1. platform
2. poweron
3. control
4. bios
5. freq
6. cache
7. misc
8. base
9. ver
10. conf

So is this looks OK to you:

1. first check for 'cpu model' if CPU not supported then goto 2
2. check for cpu_has tests

--
JSR






\
 
 \ /
  Last update: 2009-04-29 14:19    [W:0.087 / U:24.568 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site