On Fri 18 Oct 07:02 PDT 2019, Georgi Djakov wrote: > The tracepoints can help with understanding the system behavior of a > given interconnect path when the consumer drivers change their bandwidth > demands. This might be interesting when we want to monitor the requested > interconnect bandwidth for each client driver. The paths may share the > same nodes and this will help to understand "who and when is requesting > what". All this is useful for subsystem drivers developers and may also > provide hints when optimizing the power and performance profile of the > system. >
This is very useful, thanks for writing it up. > diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c [..] > @@ -449,6 +452,9 @@ int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 > peak_bw) > > /* aggregate requests for this node */ > aggregate_requests(node); > + > + trace_icc_set_bw(node, dev_name(path->reqs[i].dev), > + avg_bw, peak_bw); When I've been debugging interconnect things I've added a kstrdup_const() of "name" in of_icc_get() and then included that here. I find including the path name quite useful for devices with multiple paths. > } > > ret = apply_constraints(path); > @@ -461,6 +467,9 @@ int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 > peak_bw) > path->reqs[i].avg_bw = old_avg; > path->reqs[i].peak_bw = old_peak; > aggregate_requests(node); > + > + trace_icc_set_bw(node, dev_name(path->reqs[i].dev), > + old_avg, old_peak); > } > apply_constraints(path); And analog to e.g. the clock traces I would suggest that you trace device, path and "ret" here. Regards, Bjorn
