* Possible x2apic breakage
@ 2009-01-29 15:41 Jack Steiner
2009-01-29 16:15 ` Ingo Molnar
0 siblings, 1 reply; 3+ messages in thread
From: Jack Steiner @ 2009-01-29 15:41 UTC (permalink / raw)
To: suresh.b.siddha; +Cc: mingo, linux-kernel
Suresh -
This popped up in Ingo's x86 tree yesterday. This appears to be breaking
on our simulator running in x2apic mode. If I understand the code,
this is a real breakage and not a problem in our simulator:
arch/x86/include/asm/genapic.h
static inline unsigned int read_apic_id(void)
{
unsigned int reg;
reg = *(u32 *)(APIC_BASE + APIC_ID);
return apic->get_apic_id(reg);
}
As expected, the failure occurs right after:
Enabling x2apic
Enabled x2apic and interrupt-remapping
The next reference to apicid tries to read from mem instead of MSRs.
--- jack
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Possible x2apic breakage
2009-01-29 15:41 Possible x2apic breakage Jack Steiner
@ 2009-01-29 16:15 ` Ingo Molnar
2009-01-29 20:03 ` Jack Steiner
0 siblings, 1 reply; 3+ messages in thread
From: Ingo Molnar @ 2009-01-29 16:15 UTC (permalink / raw)
To: Jack Steiner; +Cc: suresh.b.siddha, linux-kernel
* Jack Steiner <steiner@sgi.com> wrote:
> Suresh -
>
> This popped up in Ingo's x86 tree yesterday. This appears to be breaking
> on our simulator running in x2apic mode. If I understand the code,
> this is a real breakage and not a problem in our simulator:
>
>
> arch/x86/include/asm/genapic.h
>
> static inline unsigned int read_apic_id(void)
> {
> unsigned int reg;
>
> reg = *(u32 *)(APIC_BASE + APIC_ID);
> return apic->get_apic_id(reg);
> }
>
>
> As expected, the failure occurs right after:
>
> Enabling x2apic
> Enabled x2apic and interrupt-remapping
>
> The next reference to apicid tries to read from mem instead of MSRs.
yes - Suresh sent a fix earlier today. Could you please check latest
tip/master (v2.6.29-rc3-1212-g69f3c6d or later), does it work fine in your
simulator?
And i'll also merge struct apic_ops into struct genapic - now that genapic
is unified there's no reason for the two to be separate.
Ingo
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Possible x2apic breakage
2009-01-29 16:15 ` Ingo Molnar
@ 2009-01-29 20:03 ` Jack Steiner
0 siblings, 0 replies; 3+ messages in thread
From: Jack Steiner @ 2009-01-29 20:03 UTC (permalink / raw)
To: Ingo Molnar; +Cc: suresh.b.siddha, linux-kernel
On Thu, Jan 29, 2009 at 05:15:46PM +0100, Ingo Molnar wrote:
>
> * Jack Steiner <steiner@sgi.com> wrote:
>
> > Suresh -
> >
> > This popped up in Ingo's x86 tree yesterday. This appears to be breaking
> > on our simulator running in x2apic mode. If I understand the code,
> > this is a real breakage and not a problem in our simulator:
> >
> >
> > arch/x86/include/asm/genapic.h
> >
> > static inline unsigned int read_apic_id(void)
> > {
> > unsigned int reg;
> >
> > reg = *(u32 *)(APIC_BASE + APIC_ID);
> > return apic->get_apic_id(reg);
> > }
> >
> >
> > As expected, the failure occurs right after:
> >
> > Enabling x2apic
> > Enabled x2apic and interrupt-remapping
> >
> > The next reference to apicid tries to read from mem instead of MSRs.
>
> yes - Suresh sent a fix earlier today. Could you please check latest
> tip/master (v2.6.29-rc3-1212-g69f3c6d or later), does it work fine in your
> simulator?
That fixed it. The latest tree now runs our (very limited) regression suite
of tests on all apic modes.
Thanks...
--- jack
^ permalink raw reply [flat|nested] 3+ messages in thread
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2009-01-29 16:15 ` Ingo Molnar
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