On Thu, 13 Oct 2016, Grzegorz Andrejczuk wrote:
>
> +static int phi_r3mwait_disabled;
__read_mostly please.
> +
> /*
> * Just in case our CPU detection goes bad, or you have a weird system,
> * allow a way to override the automatic disabling of MPX.
> @@ -61,6 +63,34 @@ void check_mpx_erratum(struct cpuinfo_x86 *c)
> }
> }
>
> +static int __init phir3mwait_disable(char *__unused)
> +{
> + phi_r3mwait_disabled = 1;
> +
> + return 1;
> +}
> +__setup("phir3mwait=disable", phir3mwait_disable);
This needs proper documentation in Documentation/kernel-parameters.txt
> +static void __init probe_xeon_phi_r3mwait(struct cpuinfo_x86 *c)
> +{
> + if (phi_r3mwait_disabled)
> + return;
> +
> + /*
> + * Setting ring 3 MONITOR/MWAIT for all threads
> + * when CPU is Xeon Phi Family x200
> + * This can be disabled with phir3mwait=disable cmdline switch.
And why is this information useful in this comment?
> + * We preserve the reserved values and set only 2nd bit.
This last sentence does not make any sense at all.
Thanks,
tglx
