On Wed, Nov 27, 2019 at 12:30 AM Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > > On Tue, Nov 26, 2019 at 08:02:49AM -0500, Yafang Shao wrote: > > There's one case that the processes in a memcg are all exit (due to OOM > > group or some other reasons), but the file page caches are still exist. > > These file page caches may be protected by memory.min so can't be > > reclaimed. If we can't success to restart the processes in this memcg or > > don't want to make this memcg offline, then we want to drop the file page > > caches. > > The advantage of droping this file caches is it can avoid the reclaimer > > (either kswapd or direct) scanning and reclaiming pages from all memcgs > > exist in this system, because currently the reclaimer will fairly reclaim > > pages from all memcgs if the system is under memory pressure. > > The possible method to drop these file page caches is setting the > > hard limit of this memcg to 0. Unfortunately this may invoke the OOM killer > > and generates lots of misleading outputs, that should not happen. > > You can set memory.high instead...? Well, I will take a look at memory.high and analye whether it is reliable. Thanks Yafang
