On Wed 10-10-12 13:50:21, David Rientjes wrote: > On Wed, 10 Oct 2012, Michal Hocko wrote: > > > Hi, > > I am sending the patch below as an RFC because I am not entirely happy > > about myself and maybe somebody can come up with a different approach > > which would be less hackish. > > I don't see this as hackish, I didn't like how swappiness spreads outside of the LRU scanning code... > if memory.swappiness limits access to swap then this shouldn't be > factored into the calculation, and that's what your patch fixes. > > The reason why the process with the largest rss isn't killed in this case > is because all processes have CAP_SYS_ADMIN so they get a 3% bonus; OK I should have mentioned that I have tested it as root which makes a big difference with the current upstream as totalpages are considered only if adj!=0. I have originally seen the problem in 3.0 kernel (with fe35004f applied) where the calculation is different (missing a7f638f9) and we always consider total_pages there so it doesn't depend on root or oom_score_adj. > when factoring swap into the calculation and subtracting 3% from > the score in oom_badness(), they all end up having an internal > score of 1 so they are all considered equal. It appears like the > cgroup_iter_next() iteration for memcg ooms does this in reverse > order, which is actually helpful so it will select the task that is > newer. > > The only suggestion I have to make is specify this is for > memory.swappiness in the patch title, otherwise: OK. I will also update the changelog to mention oom_score_adj and CAP_SYS_ADMIN, mark the patch for stable and repost it. > Acked-by: David Rientjes <rientjes@xxxxxxxxxx> Thanks -- 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>