Messages in this thread |  | | From | Mikael Pettersson <> | Date | Fri, 2 Feb 2001 17:28:26 +0100 | Subject | Re: [PATCH] 2.4.1-ac1 UP-APIC/NMI watchdog fixes |
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Maciej W. Rozycki writes: > I've forgotten to cc you when sending Ingo my patch-2.4.0-ac12-upapic-19 > fixes a few days ago, my apologies. Since the two patches conflict with > each other, I've merged them together and provide the result below. > Please check if it is fine for you.
Looks fine to me.
> I'm unsure about the K7_NMI_EVENT macro -- I think it should go into > include/asm-i386/msr.h, but the comment should remain here. It should get > reworded a bit in this case, I suppose, though.
I'd prefer to keep it in nmi.c -- it doesn't really have any relevance elsewhere. I made a macro of it so that I wouldn't need any #ifdef:s or long explanations in the code proper.
There is one thing which bothers me. Look at the end of the NMI handler:
> + if (cpu_has_apic && (nmi_watchdog == NMI_LOCAL_APIC)) > + wrmsr(nmi_perfctr_msr, -(cpu_khz/HZ*1000), -1);
This becomes a series of loads and tests. Ideally, a _single_ test should suffice to inform the NMI handler whether we're in NMI_LOCAL_APIC mode or not. One problem is that we aren't resetting nmi_watchdog to NMI_NONE if we fail to detect or initialise the local APIC; if we did, we could kill the cpu_has_apic test.
... however, nmi_perfctr_msr could serve this purpose since it will be non-zero if and only if (cpu_has_apic && nmi_watchdog == NMI_LOCAL_APIC). So I would actually suggest something like:
if (nmi_perfctr_msr) wrmsr(nmi_perfctr_msr, -(cpu_khz/HZ*1000), -1);
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