Hi Geneviève Please see below.
BR, Bernd On Mon, Mar 25, 2013 at 11:58 AM, Geneviève Bastien <gbast...@versatic.net> wrote: > Hi all, > > As trace analysis tools become available in TMF (trace synchronization, > critical path calculation, latency, etc), a requirement is to be able to > express dependencies between events. > > After discussions and seeing the work done so far on trace analysis, here is > a proposal for how to express and display those dependencies. > > **Modeling the dependencies** > > I'd propose to use a graph structure to represent those dependencies (a set > of vertices - an object at a given timestamp - and edges - a link between > two vertices). > > * The edges would be directed, but the graph would not necessarily be > connected. > > The graph would be > * sortable (by timestamp of vertices) > * subsettable (for a given timerange, for given processes/entries) > > Each type of trace analysis would produce its own graph of dependencies, as > the edges needed by each are not the same. Each graph will be saved to disk > as a supplementary file. > > **Displaying the dependencies** > > As for displaying those dependencies, it could be done through layers on the > Control flow view. Just like in Google Map, one could select the layers to > display and the corresponding graphs will be drawn over the control flow > view. > > In order to do this, we'll first need to modify the TimeGraphCombo (or copy > and add a new view?), the tmf widget with entries on the left and a drawing > canvas on the right, to support different layers. > > We'll have to take care not to clog the view and maybe need to sort the > entries a bit so as to limit the number of super long arrows going from an > entry at the top to an entry at the bottom. At least it should be possible > to filter the entries shown so that only those that have dependencies are > shown. > > The dependency graph could be displayed also as a sequence diagram. It could > also be exported as a dot file and visualized in external tool like > graphviz. > TMF comes with Sequence Diagram Framework which can be easily extended. So I would encourage to use this Framework to draw sequence diagrams. For more information about the TMF Sequence Diagram Framework see http://wiki.eclipse.org/Linux_Tools_Project/TMF/User_Guide#TMF_UML2_Sequence_Diagram_Framework. When we introduced the the sequence diagram framework we planned to have a declarative way (e.g in a XML) to define how to translate events to interactions and lifelines. This hasn't been done. Currently, an example java implementation (org.eclipse.linuxtools.tmf.ui.views.uml2sd.loader.TmfUml2SDSyncLoader.java) exists as reference or base for further implementations. However, maybe with the addition of a data driven state system through an XML file it is a good time to also define a data driven sequence diagram. > **Implementation** > > For now, this dependency implementation would be hardcoded for dependencies > on lttng kernel traces, but in the long run, the syntax proposed in previous > threads by Florian Wininger and Aaron Spear will be extended to be able to > support expressing the dependencies from trace events. > > For example, we should be able to express something like this (these are > just examples, exact syntax or schema will depend on what is implemented in > TMF): > > my_send_event(to=(.*),packet_no=(.*)).match(my_receive_event(to=\1,sequence=\2)) > to create an edge from the my_send_event to my_receive_event. > > or > > event: sched_switch:dependency from task(event.prev_tid) to > task(event.next_tid) > to create an edge from the previous task to the next task of a sched switch. > > > > This is the big idea. I would like to get some feedback on this proposal. > Does that make sense? Any complications ahead? Better ideas? > > Thanks, > Geneviève > > _______________________________________________ > linuxtools-dev mailing list > linuxtools-dev@eclipse.org > https://dev.eclipse.org/mailman/listinfo/linuxtools-dev _______________________________________________ linuxtools-dev mailing list linuxtools-dev@eclipse.org https://dev.eclipse.org/mailman/listinfo/linuxtools-dev
