[RFC] tracing: Adding cgroup aware tracing functionality

[Frederic Weisbecker]

On Fri, Apr 08, 2011 at 09:00:56PM +0200, Frederic Weisbecker wrote:
> On Fri, Apr 08, 2011 at 03:37:48AM -0400, Steven Rostedt wrote:
> > I actually agree, as perf is more focused on per process (or group) than
> > ftrace. But that said, I guess the issue is also, if they have a simple
> > solution that is not invasive and suits their needs, what's the harm in
> > accepting it?
> 
> What about a kind of cgroup_of(path) operator that we can use on
> filters?
> 
> 	common_pid cgroup_of(path)
> or
> 	common_pid __cgroup_of__ path
> 
> That way you don't bloat the tracing fast path?

Note in this example, we would simply ignore the common_pid
value and assume that pid is the one of current. This economizes
a step to pid -> task resolution.