Messages in this thread | | | Date | Thu, 13 Sep 2018 17:00:50 -0700 | From | Eduardo Valentin <> | Subject | Re: [PATCHv2 1/1] perf/x86/intel: make error messages less confusing |
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Hey Peter,
On Thu, Sep 06, 2018 at 09:21:49AM +0200, Peter Zijlstra wrote: > On Wed, Sep 05, 2018 at 02:47:07PM -0700, Andi Kleen wrote: > > On Wed, Sep 05, 2018 at 08:53:17AM -0700, Eduardo Valentin wrote: > > > On Wed, Sep 05, 2018 at 10:52:12AM +0200, Peter Zijlstra wrote: > > > > On Thu, Aug 23, 2018 at 08:07:32AM -0700, Eduardo Valentin wrote: > > > > > On a system with X86_FEATURE_ARCH_PERFMON disabled > > > > > and with a model not known by family PMU drivers, > > > > > user gets a kernel message log like the following: > > > > > [ 0.100114] Performance Events: unsupported p6 CPU model 85 no PMU driver, software events only. > > > > > > > > > > The "unsupported .. CPU" part may be confusing for some > > > > > users leading to wrong understanding that the kernel > > > > > does not support the CPU model. > > > > > > > > Send them back to first grade, such that they might learn to read? > > > > > > > > > > :-) > > > > I think it's a valid concern, I guess Eduardo actually has real people > > who got confused. > > But it is really easy to confuse real people; as real people are mostly > clueless. There is only so much you can do for the semi illiterate > masses. Should we dumb down everything to baby talk just to cater to > them? > > The string is clearly prefixed by the subsystem, if you get confused by > that your reading comprehension really is rock bottom. > > [ 0.100114] Performance Events: unsupported p6 CPU model 85 no PMU driver, software events only. >
Once again, the confusing part is the "unsupported CPU".
> Heck, it even mentions "no PMU driver", how much clues do you need? > Also, the proposed alternative: > > [ 0.667154] Performance Events: CPU does not support PMU: no PMU driver, software events only. > > Looses out information on which CPU family we failed on. Nor does it
Maybe keeping the CPU family and rephrasing the unsupported part?
> mention the most likely reason for this error: virt crap. > > I'd not mind a warning like: > > [] Performance Events: Your crappy virt solution is lying about it's CPU model, it doesn't have a (matching) PMU. >
Well, I would be OK if the kernel spits out a message saying that vPMU is disabled or something. That would be more accurate than unsupported CPU.
> >
-- All the best, Eduardo Valentin
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