Re: 2.6.18-rc6-mm1: GPF loop on early boot

Jeremy Fitzhardinge
2006-09-11T07:41:43Z

Ingo Molnar wrote:
> because userspace does not use it normally, while with %gs we'd switch
> between glibc's descriptor [which must be shadowed by the CPU] and the
> kernel's descriptor [which must be shadowed by the CPU too] - hence
> causing a constant reloading of the shadow register.
>

Well, that means the only operation which would be different would be
the pop %fs at the end, since only it would end up loading a null
selector. All the other operations would presumably take just as long.

J