Re: [Xen-devel] [PATCH RFC 22/31] x86/cpu: Move set_cpumask() calls into c_early_init()

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 16.12.15 at 22:24, <andrew.cooper3@xxxxxxxxxx> wrote:
> Before c/s 44e24f8567 "x86: don't call generic_identify() redundantly", the
> commandline-provided masks would take effect in Xen's view of the features.
> 
> As the masks got applied after the query for features, the redundant call to
> generic_identify() would clobber the wrong feature information with the new,
> correct information.

I don't think "wrong" is appropriate here, since ...

> Move the set_cpumask() calls into c_early_init() so their effects take place
> before the main query for features in generic_identify().
> 
> The cpuid_mask_* command line parameters now correctly limit the entire
> system,

... I consider this wrong (both Xen and Dom0 can benefit from using
features an admin may want to mask for migration purposes), the
more ...

> although the subsequent changes will replace the need to use these
> parameters for heterogeneous levelling purposes.

... that you then make clear this won't be needed anymore.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel