On Tue, Feb 21, 2006 at 05:31:59PM -0800, Chen, Kenneth W wrote: > David Gibson wrote on Tuesday, February 21, 2006 4:14 PM > > Second problem is in the hugepage logic in free_pgtables() > > (mm/memory.c). As far as I can tell it's complete crap, and only > > works by accident, for different accidental reasons on ppc64 and ia64, > > the only archs that have a non-trivial is_hugepage_only_range(). > > Except that I'm not sure it does entirely work by accident on ia64: > > suppose a process has a hugepage mapping that begins some way after > > the beginning of the hugepage address range. Before > > hugetlb_free_pgd_range() gets called on that area, it will be called > > on the next normal page VMA down - but with an end address at the > > beginning of the hugepage VMA and so extending into the hugepage > > address range. I don't really understand the ia64 pagetable mapping > > stuff well enough to tell if that's dangerous or not. > > I don't see any problem in the ia64 code. The start and end address is > what the vma specified. Floor and ceiling is just a hint for free_pgtables() > to free any left over page tables between vma holes (to prev and next). > As far as I can tell, the code looks fine. Ah, yes, I see now. free_pgd_range() only iterates through to end, not ceiling so it should be fine. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson - : send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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