Re: [PATCH] domain builder: Fix sp_extents allocation

[Samuel Thibault <samuel.thibault@eu.citrix.com>]

Keir Fraser, le Thu 31 Jul 2008 12:19:18 +0100, a écrit :
> Doesn't this turn the array allocation into a dynamic allocation? I feel a
> bit dubious about that.

> >          {
> >              long done;
> > -            xen_pfn_t sp_extents[2048 >> SUPERPAGE_PFN_SHIFT];
> > +            xen_pfn_t sp_extents[count >> SUPERPAGE_PFN_SHIFT];
> >              struct xen_memory_reservation sp_req = {

Err, I'd think that it just turns a

sub (2048>>SUPERPAGE_PFN_SHIFT) * sizeof(xen_pfn_t), %esp

into a

mov count, %eax
shr SUPERPAGE_PFN_SHIFT - log2(sizeof(xen_pfn_t)), %eax
sub %eax, %esp

Samuel