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

[Zoltan Menyhart <Zoltan.Menyhart@bull.net>]

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