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Message-ID: <2f11576a0905140727j5ba02b07t94826f57dd99839c@mail.gmail.com>
Subject: Re: [PATCH] mmtom: Prevent shrinking of active anon lru list in case 
	of no swap space V3
From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: MinChan Kim <minchan.kim@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
       LKML <linux-kernel@vger.kernel.org>, linux-mm <linux-mm@kvack.org>,
       Johannes Weiner <hannes@cmpxchg.org>, Rik van Riel <riel@redhat.com>
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>  mm/vmscan.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 2f9d555..621708f 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1577,7 +1577,7 @@ static void shrink_zone(int priority, struct zone *zone,
>         * Even if we did not try to evict anon pages at all, we want to
>         * rebalance the anon lru active/inactive ratio.
>         */
> -       if (inactive_anon_is_low(zone, sc))
> +       if (inactive_anon_is_low(zone, sc) && nr_swap_pages > 0)
>                shrink_active_list(SWAP_CLUSTER_MAX, zone, sc, priority, 0);


       if (nr_swap_pages > 0 && inactive_anon_is_low(zone, sc))

is better?
compiler can't swap evaluate order around &&.

then,

    if ( 0 && inactive_anon_is_low(zone, sc))

and

    if (inactive_anon_is_low(zone, sc) && 0)

are different.