* Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
> * Brendan Jackman <jackmanb@xxxxxxxxxx> wrote:
>
> > Hi folks, happy new year. I hope this ping isn't too aggressive given
> > the season - please let me know if it is.
> >
> > Any new thoughts on this?
>
> Sorry, this series got lost in the holiday season (apparently you
> weren't nearly pushy enough to breach the maintainer patch-detection
> noise/signal level :-), and this functionality is definitely useful and
> the series looks good to me.
>
> Integration with clearcpuid= is so much more generic than the original
> variant and reuses a lot of that logic, so that's a big plus.
>
> I've applied it to the x86 tree under the tip:x86/cpu branch and if
> everything goes fine in testing it should hit v6.15 in a couple of
> weeks.
>
> One additional thing - which I'd suggest we make a 4th patch, because
> it affects the existing clearcpuid= behavior - is to extend
> set/clearcpuid= with a bit more boot time verbosity, right now it
> taints the kernel:
>
> /* empty-string, i.e., ""-defined feature flags */
> if (!x86_cap_flags[bit])
> pr_cont(" " X86_CAP_FMT_NUM, x86_cap_flag_num(bit));
> else
> pr_cont(" " X86_CAP_FMT, x86_cap_flag(bit));
>
> if (set)
> setup_force_cpu_cap(bit);
> else
> setup_clear_cpu_cap(bit);
> taint++;
>
>
> I'd suggest we do what PeterZ suggested back in December: in addition
> to the tainting, also emit an informative pr_warn() for every CPU
> feature bit enabled/disabled over what was present, and maybe make a
> bit of a distinction between 'feature' and 'bug' feature bits.
Ie. what I mean is that at minimum upgrade the output from pr_info() to
pr_warn() - but maybe also make it clear in the output that the kernel
is tainted and things may break as a result of modifying the feature
bits.
Thanks,
Ingo
