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From: Rik van Riel <riel@redhat.com>
To: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michel Lespinasse <walken@google.com>,
	Minchan Kim <minchan.kim@gmail.com>,
	Hugh Dickins <hughd@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-mm <linux-mm@kvack.org>
Subject: Re: THP, rmap and page_referenced_one()
Date: Tue, 08 Mar 2011 08:57:46 -0500	[thread overview]
Message-ID: <4D7635DA.9030707@redhat.com> (raw)
In-Reply-To: <20110308113245.GR25641@random.random>

On 03/08/2011 06:32 AM, Andrea Arcangeli wrote:

> Subject: thp: fix page_referenced to modify mapcount/vm_flags only if page is found
>
> From: Andrea Arcangeli<aarcange@redhat.com>
>
> When vmscan.c calls page_referenced, if an anon page was created before a
> process forked, rmap will search for it in both of the processes, even though
> one of them might have since broken COW. If the child process mlocks the vma
> where the COWed page belongs to, page_referenced() running on the page mapped
> by the parent would lead to *vm_flags getting VM_LOCKED set erroneously (leading
> to the references on the parent page being ignored and evicting the parent page
> too early).

> Signed-off-by: Andrea Arcangeli<aarcange@redhat.com>
> Reported-by: Michel Lespinasse<walken@google.com>

Reviewed-by: Rik van Riel<riel@redhat.com>

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  parent reply	other threads:[~2011-03-08 13:57 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-07  6:50 THP, rmap and page_referenced_one() Michel Lespinasse
2011-03-07  7:33 ` KOSAKI Motohiro
2011-03-07  8:35 ` Minchan Kim
2011-03-07 10:35   ` Michel Lespinasse
2011-03-08 11:32     ` Andrea Arcangeli
2011-03-08 12:21       ` Michel Lespinasse
2011-03-08 12:58         ` Andrea Arcangeli
2011-03-08 22:48           ` Minchan Kim
2011-03-09  9:18           ` Johannes Weiner
2011-03-08 13:57       ` Rik van Riel [this message]
2011-03-09  7:11         ` KOSAKI Motohiro

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