Re: [PATCH -tip] x86: cpu_debug.c prepare report if files areinappropriate or CPU is not supported

From: Ingo Molnar
Date: Tue Apr 14 2009 - 14:42:37 EST



* Jaswinder Singh Rajput <jaswinder@xxxxxxxxxx> wrote:

> On Tue, 2009-04-14 at 18:50 +0200, Ingo Molnar wrote:
> > * Jaswinder Singh Rajput <jaswinder@xxxxxxxxxx> wrote:
> >
> > > + if (!per_cpu(cpu_modelflag, cpu))
> >
> > hm, on a second look - the whole cpu_model / cpu_modelflag
> > business in arch/x86/kernel/cpu/cpu_debug.c looks
> > over-complicated and broken. You encode it into a
> > 'modelflag':
> >
> > per_cpu(cpu_model, cpu) = ((cpui->x86_vendor << 16) |
> > (cpui->x86 << 8) |
> > (cpui->x86_model));
> >
> > just to decode it later on:
> >
> > flag = per_cpu(cpu_model, cpu);
> >
> > switch (flag >> 16) {
> >
> > That does not make much sense. Please use a proper
> > boot_cpu_data.x86_vendor switch() statement, ok?
> >
>
> I am using flags for each cpu, in case there are different CPU in the
> sockets:
>
> struct cpuinfo_x86 *cpui;
> cpui = &cpu_data(cpu);
>
> Do you still think that boot_cpu_data.x86_vendor is better option in
> case for multiple CPUs.

yes. Assymetric SMP never really happened on x86.

Ingo
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