On Tue, Jan 17, 2017 at 01:11:50PM +0100, Thomas Gleixner wrote: > On Fri, 6 Jan 2017, Vikas Shivappa wrote: > > > From: David Carrillo-Cisneros <davi...@google.com> > > > > cgroup hierarchy monitoring is not supported currently. This patch > > builds all the necessary datastructures, cgroup APIs like alloc, free > > etc and necessary quirks for supporting cgroup hierarchy monitoring in > > later patches. > > > > - Introduce a architecture specific data structure arch_info in > > perf_cgroup to keep track of RMIDs and cgroup hierarchical monitoring. > > - perf sched_in calls all the cgroup ancestors when a cgroup is > > scheduled in. This will not work with cqm as we have a common per pkg > > rmid associated with one task and hence cannot write different RMIds > > into the MSR for each event. cqm driver enables a flag > > PERF_EV_CGROUP_NO_RECURSION which indicates the perf to not call all > > ancestor cgroups for each event and let the driver handle the hierarchy > > monitoring for cgroup. > > - Introduce event_terminate as event_destroy is called after cgrp is > > disassociated from the event to support rmid handling of the cgroup. > > This helps cqm clean up the cqm specific arch_info. > > - Add the cgroup APIs for alloc,free,attach and can_attach > > > > The above framework will be used to build different cgroup features in > > later patches. > > That's not a framework. It's a hodgepodge of core and x86 specific changes.
Trainwreck comes to mind. It completely fails to describe semantics of the hacks and how they would preserve the cgroup invariants.
