From: Minchan Kim <minchan@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Michael Kerrisk <mtk.manpages@gmail.com>,
linux-api@vger.kernel.org, Hugh Dickins <hughd@google.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Rik van Riel <riel@redhat.com>, Mel Gorman <mgorman@suse.de>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Jason Evans <je@fb.com>, Daniel Micay <danielmicay@gmail.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>,
Shaohua Li <shli@kernel.org>, Michal Hocko <mhocko@suse.cz>,
yalin.wang2010@gmail.com, Andy Lutomirski <luto@amacapital.net>,
Minchan Kim <minchan@kernel.org>
Subject: [PATCH v5 06/12] mm: mark stable page dirty in KSM
Date: Mon, 30 Nov 2015 15:39:37 +0900 [thread overview]
Message-ID: <1448865583-2446-7-git-send-email-minchan@kernel.org> (raw)
In-Reply-To: <1448865583-2446-1-git-send-email-minchan@kernel.org>
The MADV_FREE patchset changes page reclaim to simply free a clean
anonymous page with no dirty ptes, instead of swapping it out; but
KSM uses clean write-protected ptes to reference the stable ksm page.
So be sure to mark that page dirty, so it's never mistakenly discarded.
[hughd: adjusted comments]
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---
mm/ksm.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/mm/ksm.c b/mm/ksm.c
index 30cb0f753e19..5e967536c38e 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1015,6 +1015,12 @@ static int try_to_merge_one_page(struct vm_area_struct *vma,
*/
set_page_stable_node(page, NULL);
mark_page_accessed(page);
+ /*
+ * Page reclaim just frees a clean page with no dirty
+ * ptes: make sure that the ksm page would be swapped.
+ */
+ if (!PageDirty(page))
+ SetPageDirty(page);
err = 0;
} else if (pages_identical(page, kpage))
err = replace_page(vma, page, kpage, orig_pte);
--
1.9.1
next prev parent reply other threads:[~2015-11-30 6:40 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-30 6:39 [PATCH v5 00/12] MADV_FREE support Minchan Kim
2015-11-30 6:39 ` [PATCH v5 01/12] mm: support madvise(MADV_FREE) Minchan Kim
2015-11-30 8:20 ` Mika Penttilä
2015-11-30 9:22 ` Minchan Kim
2015-11-30 6:39 ` [PATCH v5 02/12] mm: define MADV_FREE for some arches Minchan Kim
2015-11-30 6:39 ` [PATCH v5 03/12] arch: uapi: asm: mman.h: Let MADV_FREE have same value for all architectures Minchan Kim
2015-11-30 6:39 ` [PATCH v5 04/12] mm: free swp_entry in madvise_free Minchan Kim
2015-11-30 6:39 ` [PATCH v5 05/12] mm: move lazily freed pages to inactive list Minchan Kim
2015-11-30 6:39 ` Minchan Kim [this message]
2015-11-30 6:39 ` [PATCH v5 07/12] x86: add pmd_[dirty|mkclean] for THP Minchan Kim
2015-11-30 6:39 ` [PATCH v5 08/12] sparc: " Minchan Kim
2015-11-30 6:39 ` [PATCH v5 09/12] powerpc: " Minchan Kim
2015-11-30 6:39 ` [PATCH v5 10/12] arm: add pmd_mkclean " Minchan Kim
2015-11-30 6:39 ` [PATCH v5 11/12] arm64: " Minchan Kim
2015-11-30 6:39 ` [PATCH v5 12/12] mm: don't split THP page when syscall is called Minchan Kim
2016-01-28 7:16 ` [PATCH v5 00/12] MADV_FREE support Michael Kerrisk (man-pages)
2016-01-29 7:32 ` Minchan Kim
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