Re: [patch 2/3] memcg: prevent endless loop when charging huge pagesto near-limit group

[Minchan Kim]

On Mon, Jan 31, 2011 at 11:03 PM, Johannes Weiner <hannes@xxxxxxxxxxx> wrote:
> If reclaim after a failed charging was unsuccessful, the limits are
> checked again, just in case they settled by means of other tasks.
>
> This is all fine as long as every charge is of size PAGE_SIZE, because
> in that case, being below the limit means having at least PAGE_SIZE
> bytes available.
>
> But with transparent huge pages, we may end up in an endless loop
> where charging and reclaim fail, but we keep going because the limits
> are not yet exceeded, although not allowing for a huge page.
>
> Fix this up by explicitely checking for enough room, not just whether
> we are within limits.
>
> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx>


-- 
Kind regards,
Minchan Kim
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