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| author | Hugh Dickins <hugh.dickins@tiscali.co.uk> | 2009-09-22 02:03:33 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-22 16:17:41 +0200 |
| commit | 3ae77f43b1118a76ea37952d444319c15e002c03 (patch) | |
| tree | 78152c28d4c8be8da36148e2e38e87e1b08b839b /mm/hugetlb.c | |
| parent | mm: m(un)lock avoid ZERO_PAGE (diff) | |
| download | linux-3ae77f43b1118a76ea37952d444319c15e002c03.tar.xz linux-3ae77f43b1118a76ea37952d444319c15e002c03.zip | |
mm: hugetlbfs_pagecache_present
Rename hugetlbfs_backed() to hugetlbfs_pagecache_present()
and add more comments, as suggested by Mel Gorman.
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Rik van Riel <riel@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan.kim@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.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 6b41f70bbc7f..815dbd4a6dcb 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2016,8 +2016,11 @@ static struct page *hugetlbfs_pagecache_page(struct hstate *h, return find_lock_page(mapping, idx); } -/* Return whether there is a pagecache page to back given address within VMA */ -static bool hugetlbfs_backed(struct hstate *h, +/* + * Return whether there is a pagecache page to back given address within VMA. + * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page. + */ +static bool hugetlbfs_pagecache_present(struct hstate *h, struct vm_area_struct *vma, unsigned long address) { struct address_space *mapping; @@ -2254,10 +2257,13 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, /* * When coredumping, it suits get_dump_page if we just return - * an error if there's a hole and no huge pagecache to back it. + * an error where there's an empty slot with no huge pagecache + * to back it. This way, we avoid allocating a hugepage, and + * the sparse dumpfile avoids allocating disk blocks, but its + * huge holes still show up with zeroes where they need to be. */ - if (absent && - ((flags & FOLL_DUMP) && !hugetlbfs_backed(h, vma, vaddr))) { + if (absent && (flags & FOLL_DUMP) && + !hugetlbfs_pagecache_present(h, vma, vaddr)) { remainder = 0; break; } |