Re: CVS commit: src/sys/arch

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Wed, Feb 22, 2012 at 10:15:50AM +0530, Cherry G. Mathew wrote:
> Hi Manuel,
> 
> On 22 February 2012 00:40, Manuel Bouyer <bouyer%netbsd.org@localhost> wrote:
> > Module Name:    src
> > Committed By:   bouyer
> > Date:           Tue Feb 21 19:10:13 UTC 2012
> >
> > Modified Files:
> >        src/sys/arch/x86/x86: pmap.c
> >        src/sys/arch/xen/x86: cpu.c
> >
> > Log Message:
> > Avoid early use of xen_kpm_sync(); locks are not available at this time.
> > Don't call cpu_init() twice.
> >
> > Makes LOCKDEBUG kernels boot again
> >
> >
> > To generate a diff of this commit:
> > cvs rdiff -u -r1.166 -r1.167 src/sys/arch/x86/x86/pmap.c
> 
> @@ -4183,14 +4183,30 @@
>                         pte = pmap_pa2pte(pa) | PG_k | PG_V | PG_RW;
>  #ifdef XEN
>                         xpq_queue_pte_update(xpmap_ptetomach(&pdep[i]), pte);
> -                       if (level == PTP_LEVELS) {
>  #if defined(PAE) || defined(__x86_64__)
> -                               if (i >= PDIR_SLOT_KERN) {
> +                       if (level == PTP_LEVELS && i >= PDIR_SLOT_KERN) {
> +                               if (__predict_true(
> +                                   cpu_info_primary.ci_flags & 
> CPUF_PRESENT)) {
> 
> 
> Can we use that as a canonical MI method in Xen to detect if the tls
> (gs/fs) has been setup ?

probably not; it works here because we want to know if we already
probed CPUs; I'm not sure CPUF_PRESENT will garantee that
curcpu() will work.


-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--