On Fri, 1 Apr 2016, Andy Lutomirski wrote:
> +static void update_local_turbo_mode(void *dummy)
> +{
> + unsigned long cr0 = read_cr0();
> +
> + /*
> + * KVM doesn't properly handle CD.
> + *
> + * XXX: this may interact poorly with CPU hotplug.
Please cc these crazy folks who cleanup the hotplug mess so they can put it on
their todo list.
> + */
> +
> + if (turbo_mode)
> + write_cr0(cr0 & ~X86_CR0_CD);
> + else
> + write_cr0(cr0 | X86_CR0_CD);
I think proper turbo mode disable requires ~(X86_CR0_CD | X86_CR0_NW)
> +static void update_turbo_mode(void)
> +{
> + on_each_cpu(update_local_turbo_mode, NULL, 1);
> +
> + if (!turbo_mode)
> + wbinvd();
You really want to do wbinvd() on each cpu to make sure that each cpu gets out
of that turbo thing.
Thanks,
tglx
