On Fri 03-02-17 10:56:42, vinayak menon wrote: > On Thu, Feb 2, 2017 at 9:31 PM, Michal Hocko <mhocko@xxxxxxxxxx> wrote: > > > > Why would you like to chose and kill a task when the slab reclaim can > > still make sufficient progres? Are you sure that the slab contribution > > to the stats makes all the above happening? > > > I agree that a task need not be killed if sufficient progress is made > in reclaiming > memory say from slab. But here it looks like we have an impact because of just > increasing the reclaimed without touching the scanned. It could be because of > disimilar costs or not adding adding cost. I agree that vmpressure is > only a reasonable > estimate which does not already include few other costs, but I am not > sure whether it is ok > to add another element which further increases that disparity. > We noticed this problem when moving from 3.18 to 4.4 kernel version. With the > same workload, the vmpressure events differ between 3.18 and 4.4 causing the > above mentioned problem. And with this patch on 4.4 we get the same results > as in 3,18. So the slab contribution to stats is making a difference. Please document that in the changelog along with description of the workload that is affected. Ideally also add some data from /proc/vmstat so that we can see the reclaim activity. -- 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>
