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author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2010-09-10 13:23:03 +0900 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-09-23 17:29:18 -0700 |
commit | 433abed6c6f76ca079a9564f2a1a51fd28ebe0ca (patch) | |
tree | d654c3331c1910fdae732c6576d1f023b0cfae7d | |
parent | bcf835e52e0974b2e2e056b190dd66372b28cfce (diff) | |
download | op-kernel-dev-433abed6c6f76ca079a9564f2a1a51fd28ebe0ca.zip op-kernel-dev-433abed6c6f76ca079a9564f2a1a51fd28ebe0ca.tar.gz |
hugetlb, rmap: always use anon_vma root pointer
This patch applies Andrea's fix given by the following patch into hugepage
rmapping code:
commit 288468c334e98aacbb7e2fb8bde6bc1adcd55e05
Author: Andrea Arcangeli <aarcange@redhat.com>
Date: Mon Aug 9 17:19:09 2010 -0700
This patch uses anon_vma->root and avoids unnecessary overwriting when
anon_vma is already set up.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | mm/rmap.c | 13 |
1 files changed, 7 insertions, 6 deletions
@@ -1564,13 +1564,14 @@ static void __hugepage_set_anon_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address, int exclusive) { struct anon_vma *anon_vma = vma->anon_vma; + BUG_ON(!anon_vma); - if (!exclusive) { - struct anon_vma_chain *avc; - avc = list_entry(vma->anon_vma_chain.prev, - struct anon_vma_chain, same_vma); - anon_vma = avc->anon_vma; - } + + if (PageAnon(page)) + return; + if (!exclusive) + anon_vma = anon_vma->root; + anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON; page->mapping = (struct address_space *) anon_vma; page->index = linear_page_index(vma, address); |