Re: [PATCH 1/2] x86: eliminate TS_XSAVE

Suresh Siddha
2010-05-04T18:03:29Z

On Sun, 2010-05-02 at 07:53 -0700, Avi Kivity wrote:
> The fpu code currently uses current->thread_info->status & TS_XSAVE as
> a way to distinguish between XSAVE capable processors and older processors.
> The decision is not really task specific; instead we use the task status to
> avoid a global memory reference - the value should be the same across all
> threads.
>
> Eliminate this tie-in into the task structure by using an alternative
> instruction keyed off the XSAVE cpu feature; this results in shorter and
> faster code, without introducing a global memory reference.
>
> Signed-off-by: Avi Kivity <avi@redhat.com>

Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>