From 08fba69986e20c1c9e5fe2e6064d146cc4f42480 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 6 Jan 2009 14:38:53 -0800 Subject: 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 Acked-by: "KOSAKI Motohiro" Cc: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'mm') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 6058b53dcb89..5cb8bc7c80f7 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -219,6 +219,22 @@ static pgoff_t vma_hugecache_offset(struct hstate *h, (vma->vm_pgoff >> huge_page_order(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 -- cgit v1.2.1