| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.10 19/56] vmscan: fix increasing nr_isolated incurred by putback unevictable pages | Date | Tue, 29 Sep 2015 15:47:07 +0200 |
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3.10-stable review patch. If anyone has any objections, please let me know.
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From: Jaewon Kim <jaewon31.kim@samsung.com>
commit c54839a722a02818677bcabe57e957f0ce4f841d upstream.
reclaim_clean_pages_from_list() assumes that shrink_page_list() returns number of pages removed from the candidate list. But shrink_page_list() puts back mlocked pages without passing it to caller and without counting as nr_reclaimed. This increases nr_isolated.
To fix this, this patch changes shrink_page_list() to pass unevictable pages back to caller. Caller will take care those pages.
Minchan said:
It fixes two issues.
1. With unevictable page, cma_alloc will be successful.
Exactly speaking, cma_alloc of current kernel will fail due to unevictable pages.
2. fix leaking of NR_ISOLATED counter of vmstat
With it, too_many_isolated works. Otherwise, it could make hang until the process get SIGKILL.
Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -925,7 +925,7 @@ cull_mlocked: if (PageSwapCache(page)) try_to_free_swap(page); unlock_page(page); - putback_lru_page(page); + list_add(&page->lru, &ret_pages); continue; activate_locked:
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