On Tue 24-03-20 20:30:32, teawater wrote: > > > > 2020年3月24日 19:00，Michal Hocko <mhocko@xxxxxxxxxx> 写道： > > > > On Tue 24-03-20 18:31:56, Hui Zhu wrote: > >> /sys/kernel/mm/transparent_hugepage/enabled is the only interface to > >> control if the application can use THP in system level. > >> Sometime, we would not want an application use THP even if > >> transparent_hugepage/enabled is set to "always" or "madvise" because > >> thp may need more cpu and memory resources in some cases. > > > > Could you specify that sometime by a real usecase in the memcg context > > please? > > > Thanks for your review. > > We use thp+balloon to supply more memory flexibility for vm. > https://lore.kernel.org/linux-mm/1584893097-12317-1-git-send-email-teawater@xxxxxxxxx/ > This is another thread that I am working around thp+balloon. > > Other applications are already deployed on these machines. The > transparent_hugepage/enabled is set to never because they used to have > a lot of THP related performance issues. And some of them may call > madvise thp with itself. If they call madvise then they clearly indicate they prefer THP regardless the cost. So I really fail to see what memcg specific tuning brings in. Could you be more specific about the usecase that cannot work with the existing THP tuning? -- Michal Hocko SUSE Labs
