Messages in this thread | | | Date | Fri, 11 Jul 2008 09:17:34 +0100 | From | Andy Whitcroft <> | Subject | Re: [PATCH 2/2] [PATCH] Align faulting address to a hugepage boundary before unmapping |
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On Thu, Jul 10, 2008 at 06:30:41PM +0100, Mel Gorman wrote: > > When taking a fault for COW on a private mapping it is possible that the > parent will have to steal the original page from its children due to an > insufficient hugepage pool. In this case, unmap_ref_private() is called > for the faulting address to unmap via unmap_hugepage_range(). This patch > ensures that the address used for unmapping is hugepage-aligned. > > Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Clearly far too many of our tests use page aligned accesss to trigger behaviour.
> mm/hugetlb.c | 1 + > 1 file changed, 1 insertion(+) > > diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.26-rc8-mm1-clean/mm/hugetlb.c linux-2.6.26-rc8-mm1-fix-needsreserve-check/mm/hugetlb.c > --- linux-2.6.26-rc8-mm1-clean/mm/hugetlb.c 2008-07-08 11:54:34.000000000 -0700 > +++ linux-2.6.26-rc8-mm1-fix-needsreserve-check/mm/hugetlb.c 2008-07-08 15:50:00.000000000 -0700 > @@ -1767,6 +1767,7 @@ int unmap_ref_private(struct mm_struct * > * vm_pgoff is in PAGE_SIZE units, hence the different calculation > * from page cache lookup which is in HPAGE_SIZE units. > */ > + address = address & huge_page_mask(hstate_vma(vma)); > pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) > + (vma->vm_pgoff >> PAGE_SHIFT); > mapping = (struct address_space *)page_private(page);
-apw
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