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authorMel Gorman <mel@csn.ul.ie>2009-01-06 14:38:53 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-06 15:58:58 -0800
commit08fba69986e20c1c9e5fe2e6064d146cc4f42480 (patch)
tree40bd36a6778624527d91ede0eb51aa5b99aab01c /mm/hugetlb.c
parent238c6d54830c624f34ac9cf123ac04aebfca5013 (diff)
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mm: report the pagesize backing a VMA in /proc/pid/smaps
It is useful to verify a hugepage-aware application is using the expected pagesizes for its memory regions. This patch creates an entry called KernelPageSize in /proc/pid/smaps that is the size of page used by the kernel to back a VMA. The entry is not called PageSize as it is possible the MMU uses a different size. This extension should not break any sensible parser that skips lines containing unrecognised information. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: "KOSAKI Motohiro" <kosaki.motohiro@jp.fujitsu.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/hugetlb.c')
-rw-r--r--mm/hugetlb.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 6058b53dcb89..5cb8bc7c80f7 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -220,6 +220,22 @@ static pgoff_t vma_hugecache_offset(struct hstate *h,
}
/*
+ * Return the size of the pages allocated when backing a VMA. In the majority
+ * cases this will be same size as used by the page table entries.
+ */
+unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
+{
+ struct hstate *hstate;
+
+ if (!is_vm_hugetlb_page(vma))
+ return PAGE_SIZE;
+
+ hstate = hstate_vma(vma);
+
+ return 1UL << (hstate->order + PAGE_SHIFT);
+}
+
+/*
* Flags for MAP_PRIVATE reservations. These are stored in the bottom
* bits of the reservation map pointer, which are always clear due to
* alignment.