Re: [PATCH] mm: Fix to infinite churning of mlocked page

From: KOSAKI Motohiro
Date: Fri Aug 21 2009 - 07:19:11 EST


2009/8/20 Rik van Riel <riel@xxxxxxxxxx>:
> Minchan Kim wrote:
>>
>> Mlocked page might lost the isolatation race.
>> It cause the page to clear PG_mlocked while it remains
>> in VM_LOCKED vma. It means it can be put [in]active list.
>> We can rescue it by try_to_unmap in shrink_page_list.
>>
>> But now, As Wu Fengguang pointed out, vmscan have a bug.
>> If the page has PG_referenced, it can't reach try_to_unmap
>> in shrink_page_list but put into active list. If the page
>> is referenced repeatedly, it can remain [in]active list
>> without moving unevictable list.
>>
>> This patch can fix it.
>>
>> Reported-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
>> Signed-off-by: Minchan Kim <minchan.kim@xxxxxxxxx>
>> Cc: KOSAKI Motohiro <<kosaki.motohiro@xxxxxxxxxxxxxx>
>> Cc: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
>> Cc: Rik van Riel <riel@xxxxxxxxxx>
>
> Acked-by: Rik van Riel <riel@xxxxxxxxxx>

Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
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