Re: [patch 2/3] mm: memcontrol: simplify detecting when the memory+swap limit is hit

Vladimir Davydov
2014-09-24T15:14:21Z

On Wed, Sep 24, 2014 at 11:08:57AM -0400, Johannes Weiner wrote:
> When attempting to charge pages, we first charge the memory counter
> and then the memory+swap counter. If one of the counters is at its
> limit, we enter reclaim, but if it's the memory+swap counter, reclaim
> shouldn't swap because that wouldn't change the situation. However,
> if the counters have the same limits, we never get to the memory+swap
> limit. To know whether reclaim should swap or not, there is a state
> flag that indicates whether the limits are equal and whether hitting
> the memory limit implies hitting the memory+swap limit.
>
> Just try the memory+swap counter first.
>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>

Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>