On Tue 23-04-13 17:13:20, Glauber Costa wrote: > On 04/23/2013 05:06 PM, Michal Hocko wrote: > > On Tue 23-04-13 05:51:36, Michel Lespinasse wrote: > > [...] > >> The issue I see is that even when people configure soft limits B+C < > >> A, your current proposal still doesn't "leave the other alone" as > >> Glauber and I think we should. > > > > If B+C < A then B resp. C get reclaimed only if A is over the limit > > which means that it couldn't reclaimed enough to get bellow the limit > > when we bang on it before B and C. We can update the implementation > > later to be more clever in situations like this but this is not that > > easy because once we get away from the round robin over the tree then we > > might end up having other issues - like unfairness etc... That's why I > > wanted to have this as simple as possible. > > > Nobody is opposing this, Michal. > > What people are opposing is you saying that the children should be > reclaimed *regardless* of their softlimit when the parent is over their > soft limit. Someone, specially you, saying this, highly threatens > further development in this direction. OK, I am feeling like repeating myself. Anyway once more. I am _all_ for protecting children that are under their limit if that is _possible_[1]. We are not yet there though for generic configuration. That's why I was so careful about the wording and careful configuration at this stage. Is this sufficient for your concerns? I do not see any giant obstacles in the current implementation to allow this behavior. > It doesn't really matter if your current set is doing this, simply > everybody already agreed that you are moving in a good direction. > > If you believe that it is desired to protect the children from reclaim > in situation in which the offender is only one of the children and that > can be easily identified, please state that clearly. Clearly yes. --- [1] and to be even more clear there are cases where this will never be possible. For an example: A (soft:0) | B (soft:MAX) where B smart ass thinks that his group never gets reclaim although he is the only source of the pressure. This is what I call untrusted environment. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>