diff options
| author | Wang, Yalin <Yalin.Wang@sonymobile.com> | 2015-02-11 15:24:51 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-11 17:06:00 -0800 |
| commit | 56873f43abdcd574b25105867a990f067747b2f4 (patch) | |
| tree | be55c69ee61da7b4e10e46c89e62a2ca68adaf81 /fs/proc/page.c | |
| parent | 1d148e218a0d0566b1c06f2f45f1436d53b049b2 (diff) | |
| download | lwn-56873f43abdcd574b25105867a990f067747b2f4.tar.gz lwn-56873f43abdcd574b25105867a990f067747b2f4.zip | |
mm:add KPF_ZERO_PAGE flag for /proc/kpageflags
Add KPF_ZERO_PAGE flag for zero_page, so that userspace processes can
detect zero_page in /proc/kpageflags, and then do memory analysis more
accurately.
Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/page.c')
| -rw-r--r-- | fs/proc/page.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/fs/proc/page.c b/fs/proc/page.c index 1e3187da1fed..7eee2d8b97d9 100644 --- a/fs/proc/page.c +++ b/fs/proc/page.c @@ -5,6 +5,7 @@ #include <linux/ksm.h> #include <linux/mm.h> #include <linux/mmzone.h> +#include <linux/huge_mm.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/hugetlb.h> @@ -121,9 +122,18 @@ u64 stable_page_flags(struct page *page) * just checks PG_head/PG_tail, so we need to check PageLRU/PageAnon * to make sure a given page is a thp, not a non-huge compound page. */ - else if (PageTransCompound(page) && (PageLRU(compound_head(page)) || - PageAnon(compound_head(page)))) - u |= 1 << KPF_THP; + else if (PageTransCompound(page)) { + struct page *head = compound_head(page); + + if (PageLRU(head) || PageAnon(head)) + u |= 1 << KPF_THP; + else if (is_huge_zero_page(head)) { + u |= 1 << KPF_ZERO_PAGE; + u |= 1 << KPF_THP; + } + } else if (is_zero_pfn(page_to_pfn(page))) + u |= 1 << KPF_ZERO_PAGE; + /* * Caveats on high order pages: page->_count will only be set |