Messages in this thread | | | Date | Sun, 10 Dec 2023 11:39:05 +0100 | From | Guilherme Amadio <> | Subject | Re: [PATCH] x86/nmi: Rate limit unknown NMI messages |
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On Fri, Dec 08, 2023 at 05:52:11PM -0800, Namhyung Kim wrote: > On some AMD machines, unknown NMI messages were printed on the console > continuously when using perf command with IBS. It was reported that it > can slow down the kernel. Let's ratelimit the unknown NMI messages. > > Cc: Ravi Bangoria <ravi.bangoria@amd.com> > Cc: Guilherme Amadio <amadio@gentoo.org>
The rate of messages on the console were proportional to the sampling frequency when I noticed this happening, so this is a welcome change. Thank you!
Acked-by: Guilherme Amadio <amadio@gentoo.org>
Best regards, -Guilherme
> Cc: Stephane Eranian <eranian@google.com> > Signed-off-by: Namhyung Kim <namhyung@kernel.org> > --- > arch/x86/kernel/nmi.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c > index 17e955ab69fe..d23867901186 100644 > --- a/arch/x86/kernel/nmi.c > +++ b/arch/x86/kernel/nmi.c > @@ -303,13 +303,13 @@ unknown_nmi_error(unsigned char reason, struct pt_regs *regs) > > __this_cpu_add(nmi_stats.unknown, 1); > > - pr_emerg("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", > - reason, smp_processor_id()); > + pr_emerg_ratelimited("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", > + reason, smp_processor_id()); > > if (unknown_nmi_panic || panic_on_unrecovered_nmi) > nmi_panic(regs, "NMI: Not continuing"); > > - pr_emerg("Dazed and confused, but trying to continue\n"); > + pr_emerg_ratelimited("Dazed and confused, but trying to continue\n"); > } > NOKPROBE_SYMBOL(unknown_nmi_error); > > -- > 2.43.0.472.g3155946c3a-goog >
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