On Mon 04-04-22 21:14:40, Zhaoyang Huang wrote: [...] > Please be noticed that this patch DOES protect the memcg when external > pressure is 1GB as fixed low does. This is getting more and more confusing (at least to me). Could you describe the behavior of the reclaim for the following setups/situations? a) mostly reclaiming a clean page cache - via kswapd b) same as above but the direct reclaim is necessary but very lightweight c) direct reclaim makes fwd progress but not enough to satisfy the allocation request (so the reclaim has to be retried) d) direct reclaim not making progress and low limit protection is ignored. Say we have several memcgs and only some have low memory protection configured. What is the user observable state of the protected group and when and how much the protection can be updated? I think it would be also helpful to describe the high level semantic of this feature. > Besides, how does the admin decide > the exact number of low/min if it expand from small to even xGB in a > quick changing scenario? This is not really related, is it? There are different ways to tune for the protection. [...] -- Michal Hocko SUSE Labs
