On Fri, May 28, 2010 at 03:48:24PM +0100, Mel Gorman wrote: > On Fri, May 28, 2010 at 09:29:16AM +0900, Naoya Horiguchi wrote: > > This patch adds reverse mapping feature for hugepage by introducing > > mapcount for shared/private-mapped hugepage and anon_vma for > > private-mapped hugepage. > > > > While hugepage is not currently swappable, reverse mapping can be useful > > for memory error handler. > > > > Without this patch, memory error handler cannot identify processes > > using the bad hugepage nor unmap it from them. That is: > > - for shared hugepage: > > we can collect processes using a hugepage through pagecache, > > but can not unmap the hugepage because of the lack of mapcount. > > - for privately mapped hugepage: > > we can neither collect processes nor unmap the hugepage. > > This patch solves these problems. > > > > This patch include the bug fix given by commit 23be7468e8, so reverts it. > > > > Dependency: > > "hugetlb: move definition of is_vm_hugetlb_page() to hugepage_inline.h" > > > > ChangeLog since May 24. > > - create hugetlb_inline.h and move is_vm_hugetlb_index() in it. > > - move functions setting up anon_vma for hugepage into mm/rmap.c. > > > > ChangeLog since May 13. > > - rebased to 2.6.34 > > - fix logic error (in case that private mapping and shared mapping coexist) > > - move is_vm_hugetlb_page() into include/linux/mm.h to use this function > > from linear_page_index() > > - define and use linear_hugepage_index() instead of compound_order() > > - use page_move_anon_rmap() in hugetlb_cow() > > - copy exclusive switch of __set_page_anon_rmap() into hugepage counterpart. > > - revert commit 24be7468 completely > > > > Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> > > Cc: Andi Kleen <andi@xxxxxxxxxxxxxx> > > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > > Cc: Wu Fengguang <fengguang.wu@xxxxxxxxx> > > Cc: Mel Gorman <mel@xxxxxxxxx> > > Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> > > Cc: Larry Woodman <lwoodman@xxxxxxxxxx> > > Cc: Lee Schermerhorn <Lee.Schermerhorn@xxxxxx> > > Ok, I could find no other problems with the hugetlb side of things in the > first two patches. I haven't looked at the hwpoison parts but I'm assuming > Andi has looked at those already. Thanks > > Acked-by: Mel Gorman <mel@xxxxxxxxx> The hwpoison part looks good. We actually start by adding ugly code in memory-failure.c to special handle huge pages, then decided that hugetlb rmap is the way to go :) Acked-by: Wu Fengguang <fengguang.wu@xxxxxxxxx> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>