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SubjectRe: [PATCH] perf_counter: powerpc: add nmi_enter/nmi_exit calls

* Paul Mackerras <paulus@samba.org> wrote:

> Impact: powerpc bug fix
>
> Now that the core is using in_nmi() (added in e30e08f6,
> "perf_counter: fix NMI race in task clock"), we need the powerpc
> perf_counter_interrupt to call nmi_enter() and nmi_exit() in those
> cases where the interrupt happens when interrupts are
> soft-disabled. If interrupts were soft-enabled, we can treat it
> as a regular interrupt and do irq_enter/irq_exit around the whole
> routine. This lets us get rid of the test_perf_counter_pending()
> call at the end of perf_counter_interrupt, thus simplifying things
> a little.

applied, thanks Paul!

I'm wondering, what was the real impact? Was it a crash or some
other misbehavior? This impact line:

Impact: powerpc bug fix

is a bit too generic to be useful in practice. Something like:

Impact: fix stuck NMIs on powerpc
Impact: fix NMI crash on powerpc

would have been more descriptive about the real, hands-on impact of
this patch.

Ingo


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