| Subject | [PATCH 09 of 66] clear compound mapping | Date | Wed, 03 Nov 2010 16:27:44 +0100 | From | Andrea Arcangeli <> |
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From: Andrea Arcangeli <aarcange@redhat.com>
Clear compound mapping for anonymous compound pages like it already happens for regular anonymous pages. But crash if mapping is set for any tail page, also the PageAnon check is meaningless for tail pages. This check only makes sense for the head page, for tail page it can only hide bugs and we definitely don't want to hide bugs.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> ---
diff --git a/mm/page_alloc.c b/mm/page_alloc.c --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -646,13 +646,10 @@ static bool free_pages_prepare(struct pa trace_mm_page_free_direct(page, order); kmemcheck_free_shadow(page, order); - for (i = 0; i < (1 << order); i++) { - struct page *pg = page + i; - - if (PageAnon(pg)) - pg->mapping = NULL; - bad += free_pages_check(pg); - } + if (PageAnon(page)) + page->mapping = NULL; + for (i = 0; i < (1 << order); i++) + bad += free_pages_check(page + i); if (bad) return false;
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