Re: [rfc] dynamic 3-level / 4-level page table

Zoltan Menyhart
2006-05-02T08:28:08Z

Chen, Kenneth W wrote:
...
> @@ -216,21 +216,11 @@ ENTRY(vhpt_miss)
> * r18 = *pte
> */
> ld8 r25=[r21] // read *pte again
> - ld8 r26=[r17] // read *pmd again
> -#ifdef CONFIG_PGTABLE_4
> - ld8 r19=[r28] // read *pud again
> -#endif
> - cmp.ne p6,p7=r0,r0
> ;;
> - cmp.ne.or.andcm p6,p7=r26,r20 // did *pmd change
> -#ifdef CONFIG_PGTABLE_4
> - cmp.ne.or.andcm p6,p7=r19,r29 // did *pud change
> -#endif
...
You explained me a month ago why pud...pmd pointers are re-checked
in "vhpt_miss".

Later I pointed out that *pgd has to be re-read and compared, too.

Could you please explain why you think it is not necessary any
more to re-check them?

Thanks,

Zoltan