On Mon, May 29, 2017 at 12:15:14PM +0300, Alexey Budankov wrote:
> On 29.05.2017 10:46, Peter Zijlstra wrote:
> > On Sat, May 27, 2017 at 02:19:51PM +0300, Alexey Budankov wrote:

> > > @@ -742,7 +772,17 @@ struct perf_event_context {
> > > 
> > >           struct list_head                active_ctx_list;
> > >           struct list_head                pinned_groups;
> > > + /*
> > > +  * Cpu tree for pinned groups; keeps event's group_node nodes
> > > +  * of attached flexible groups;
> > > +  */
> > > + struct rb_root                  pinned_tree;
> > >           struct list_head                flexible_groups;
> > > + /*
> > > +  * Cpu tree for flexible groups; keeps event's group_node nodes
> > > +  * of attached flexible groups;
> > > +  */
> > > + struct rb_root                  flexible_tree;
> > >           struct list_head                event_list;
> > >           int                             nr_events;
> > >           int                             nr_active;
> > > @@ -758,6 +798,7 @@ struct perf_event_context {
> > >            */
> > >           u64                             time;
> > >           u64                             timestamp;
> > > + struct perf_event_tstamp        tstamp_data;
> > > 
> > >           /*
> > >            * These fields let us detect when two contexts have both
> > 
> > 
> > So why do we now have a list _and_ a tree for the same entries?

> We need groups list to iterate through all groups configured for collection
> and we need the tree to quickly iterate through the groups allocated for a
> particular CPU only.

*confused*, what?

Why can't the tree do both?

Reply via email to