Re: [PATCH 14/14] skip readahead if the cgroup is congested

From: Tejun Heo
Date: Mon Jul 02 2018 - 17:14:07 EST

On Fri, Jun 29, 2018 at 03:25:42PM -0400, Josef Bacik wrote:
> From: Josef Bacik <jbacik@xxxxxx>
> We noticed in testing we'd get pretty bad latency stalls under heavy
> pressure because read ahead would try to do its thing while the cgroup
> was under severe pressure. If we're under this much pressure we want to
> do as little IO as possible so we can still make progress on real work
> if we're a throttled cgroup, so just skip readahead if our group is
> under pressure.
> Signed-off-by: Josef Bacik <jbacik@xxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>