Quoting Tvrtko Ursulin (2017-07-18 15:36:04) > From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> > > Rough sketch of the idea I mentioned a few times to various people - merging > the engine busyness tracking with Chris i915 PMU RFC. > > First patch is the actual PMU RFC by Chris. It is followed by some cleanup > patches, then come a few improvements, cheap execlists engine busyness tracking, > debugfs view for the same, and finally the i915 PMU is extended to use this > instead of timer based mmio sampling. > > This makes it cheaper and also more accurate since engine busyness is not > derived via sampling. > > But I haven't figure out the perf API yet. For example is it possible to access > our events in an usable fashion via perf top/stat or something? Do we want to > make the events discoverable as I did (patch 8). In my dreams I have gpu activity in the same perf timechart as gpu activity. But that can be mostly by the request tracepoints, but still overlaying cpu/gpu activity is desirable and more importantly we want to coordinate with nouveau/amdgpu so that such interfaces are as agnostic as possible. There are definitely a bunch of global features in common for all (engine enumeration & activity, mempool enumeration, size & activty, power usage?). But the key question is how do we build for the future? Split the event id range into common/driver? > I could not find much (any?) kernel API level documentation for perf. There isn't much indeed. Given that we now have a second pair of eyes go over the sampling and improve its interaction with i915, we should start getting PeterZ involved to check the interaction with perf. > Btw patch series actually works since intel-gpu-overlay can use these events > when they are available. > > Chris Wilson (1): > RFC drm/i915: Expose a PMU interface for perf queries One thing I would like is for any future interface (including this engine/class/event id) to use the engine class/instance mapping. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
