On Tue, Aug 30, 2016 at 09:57:02PM +0530, Hari Bathini wrote: > Currently, there is no mechanism to filter events based on containers. > perf -G can be used, but it will not filter events for the containers > created after perf is invoked, making it difficult to assess/analyze > performance issues of multiple containers at once. This limitation can > be overcome, if there is a standard kernel identifier for containers. > > This patch introduces a container identifier entry field in perf sample > data to identify or distinguish sample data of different containers. It > uses the cgroup namespace inode number of a given task as it's container > identifier (cid). Alternatively, inode number of pid namespace can also > be used as cid. This patch assumes each container is created with it's > own cgroup namespace.
I'm thinking this value is mostly the same for tasks, just like COMM and MMAP. Could we therefore not emit (sideband) events whenever a task changes namespace and get the same information but with tons less data? That also gives the possibility of recording all namespaces, not just the one.
