On Wed 30-10-24 16:33:08, gutierrez.asier@xxxxxxxxxxxxxxxxxxx wrote: > From: Asier Gutierrez <gutierrez.asier@xxxxxxxxxxxxxxxxxxx> > > Currently THP modes are set globally. It can be an overkill if only some > specific app/set of apps need to get benefits from THP usage. Moreover, various > apps might need different THP settings. Here we propose a cgroup-based THP > control mechanism. > > THP interface is added to memory cgroup subsystem. Existing global THP control > semantics is supported for backward compatibility. When THP modes are set > globally all the changes are propagated to memory cgroups. However, when a > particular cgroup changes its THP policy, the global THP policy in sysfs remains > the same. Do you have any specific examples where this would be benefitial? > New memcg files are exposed: memory.thp_enabled and memory.thp_defrag, which > have completely the same format as global THP enabled/defrag. > > Child cgroups inherit THP settings from parent cgroup upon creation. Particular > cgroup mode changes aren't propagated to child cgroups. So this breaks hierarchical property, doesn't it? In other words if a parent cgroup would like to enforce a certain policy to all descendants then this is not really possible. -- Michal Hocko SUSE Labs
