Re: [PATCH] Intel thermal monitor for x86_64

From: Zwane Mwaikambo
Date: Sun Nov 14 2004 - 20:10:07 EST

On Sun, 14 Nov 2004, Andi Kleen wrote:

> On Sat, Nov 13, 2004 at 11:36:47AM -0700, Zwane Mwaikambo wrote:
> > Patch adds support for notification of overheating conditions on intel
> > x86_64 processors. Tested on EM64T, test booted on AMD64.
> >
> > Hardware courtesy of Intel Corporation
> Did you actually execute the code by faking/forcing such a event?

Forced the event ;)

> > +#if defined(CONFIG_X86_MCE_INTEL)
> > +ENTRY(thermal_interrupt)
> > + apicinterrupt THERMAL_APIC_VECTOR,smp_thermal_interrupt
> > +#endif
> Cleaner would be probably to add a weak dummy smp_thermal_interrupt
> in traps.c and drop all the ifdefs.

Ok i can do that, weak functions tend to get different reactions from
different people, so i rarely use them in submitted code.

> Maybe this should be made a different taint bit?

Hmm, i'm not sure, if the cpu trips the overheating condition the other
components may not be running within specification either. I think let's
be cautious and just set the taint bit.

> > + } else {
> > + cpu_clear(smp_processor_id(), cpu_thermal_status);
> > + }
> > +
> > + if (time_after(jiffies, next_thermal_check))
> > + tasklet_schedule(&thermal_tasklet);
> I think there is actually a better way to do this (sorry for telling
> you late, but I also only realized it later). Can you just make
> the thermal APIC interrupt non NMI? Then the normal locking rules
> apply and printk should work directly.

It's not actually an NMI, it's delivered via FIXED delivery mode and is
maskable. I thought you had some sort of aversion towards using printk
within that context.

> Also can you at least additionally log an synthetic event using mce_log() ?
> This way someone collecting these log entries centrally get its it
> all in the same log file.

Ok, then i think we need to make the mce logging capable of storing
extended information, is the code i did for i386 ok with you?


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