Messages in this thread |  | | Date | 14 Feb 2007 10:15:04 +0100 | Date | Wed, 14 Feb 2007 10:15:04 +0100 | From | Andi Kleen <> | Subject | Re: [Xen-devel] Re: [patch 05/21] Xen-paravirt: paravirt_ops: allocate a fixmap slot |
| |
On Wed, Feb 14, 2007 at 08:37:26AM +0000, Jan Beulich wrote: > >>> Jeremy Fitzhardinge <jeremy@goop.org> 14.02.07 02:36 >>> > >Dan Hecht wrote: > >> Why doesn't Xen allocate the shared_info page from the pseudo-physical > >> space? Doesn't it already have to steal pages from the > >> pseudo-physical space for e.g. initial page tables, console, etc? Why > >> not do the same for shared_info, and then you don't need a reserve the > >> fixmap slot. > > > >Unlike the pagetable pages or the console page, the shared info page > >doesn't have a pseudo-physical address, so in order to map it we need to > >directly construct a pte containing the mfn for that page. Inserting > >this mapping into the fixmap space seems like the easiest way to do > >this. It's not like a fixmap slot costs anything. > > Otoh there are many fixmap slots not used under Xen, perhaps it would > be possible to use one of those... One slot certainly doesn't cost a lot,
I don't have a problem with reserving one page for this.
-Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |