Messages in this thread |  | | | Date | Sat, 08 Aug 2009 18:28:10 -0700 | | From | "H. Peter Anvin" <> | | Subject | Re: [PATCH] OOPS in identify_cpu() on CPUs without CPUID |
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On 08/08/2009 10:53 AM, Ingo Molnar wrote: > > indeed ... > >> Signed-off-by: Ondrej Zary <linux@rainbow-software.org> >> >> --- linux-2.6.30.4-orig/arch/x86/kernel/cpu/common.c 2009-06-10 05:05:27.000000000 +0200 >> +++ linux-2.6.30.4-router/arch/x86/kernel/cpu/common.c 2009-08-08 18:00:21.000000000 +0200 >> @@ -699,6 +699,7 @@ >> >> static void __cpuinit generic_identify(struct cpuinfo_x86 *c) >> { >> + this_cpu = &default_cpu; >> c->extended_cpuid_level = 0; >> >> if (!have_cpuid_p()) > > How about initializing this_cpu instead, via: > > static const struct cpu_dev *this_cpu __cpuinitdata = &default_cpu; >
The whole this_cpu hack is scary as all hell... although it's probably OK on a technicality, it takes what is properly a per-cpu attribute and turns it into a static global.
We *should* be able to initialize the APs (at least) in parallel, and although there probably aren't any systems in the field which don't have duplicate vendors, it is at least theoretically possible to have combinations of CPUID and non-CPUID processors in the same systems.
As such, it really would be better if this_cpu was changed to be passed as return values and on the stack (as appropriate). However, that is not 2.6.31 material, and as such doing the static initialization would be okay.
Ondrej, would you be interested in doing a "fullblown" patch for this?
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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