Re: Hugetlb demanding paging for -mm tree

William Lee Irwin III
2004-08-06T21:07:50Z

On Fri, Aug 06, 2004 at 01:55:38PM -0700, Chen, Kenneth W wrote:
> diff -Nurp linux-2.6.7/mm/hugetlb.c linux-2.6.7.hugetlb/mm/hugetlb.c
> --- linux-2.6.7/mm/hugetlb.c 2004-08-06 11:44:59.000000000 -0700
> +++ linux-2.6.7.hugetlb/mm/hugetlb.c 2004-08-06 13:15:24.000000000 -0700
> @@ -276,9 +276,10 @@ retry:
> }
>
> spin_lock(&mm->page_table_lock);
> - if (pte_none(*pte))
> + if (pte_none(*pte)) {
> set_huge_pte(mm, vma, page, pte, vma->vm_flags & VM_WRITE);
> - else
> + update_mmu_cache(vma, addr, *pte);
> + } else
> put_page(page);
> out:
> spin_unlock(&mm->page_table_lock);

update_mmu_cache() does not appear to check the size of the translation
to be established in many architectures. e.g. on arch/ia64/ it does
flush_icache_range(addr, addr + PAGE_SIZE) unconditionally, and only
sets PG_arch_1 on a single struct page. Similar comments apply to
sparc64 and ppc64; I didn't check any others.

-- wli