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authorMel Gorman <mel@csn.ul.ie>2009-01-06 17:38:53 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-06 18:58:58 -0500
commit08fba69986e20c1c9e5fe2e6064d146cc4f42480 (patch)
tree40bd36a6778624527d91ede0eb51aa5b99aab01c /mm/hugetlb.c
parent238c6d54830c624f34ac9cf123ac04aebfca5013 (diff)
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 6058b53dcb8..5cb8bc7c80f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -220,6 +220,22 @@ static pgoff_t vma_hugecache_offset(struct hstate *h,
220} 220}
221 221
222/* 222/*
223 * Return the size of the pages allocated when backing a VMA. In the majority
224 * cases this will be same size as used by the page table entries.
225 */
226unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
227{
228 struct hstate *hstate;
229
230 if (!is_vm_hugetlb_page(vma))
231 return PAGE_SIZE;
232
233 hstate = hstate_vma(vma);
234
235 return 1UL << (hstate->order + PAGE_SHIFT);
236}
237
238/*
223 * Flags for MAP_PRIVATE reservations. These are stored in the bottom 239 * Flags for MAP_PRIVATE reservations. These are stored in the bottom
224 * bits of the reservation map pointer, which are always clear due to 240 * bits of the reservation map pointer, which are always clear due to
225 * alignment. 241 * alignment.