On Wed, 2017-08-23 at 20:04 +0200, Peter Zijlstra wrote: > On Wed, Aug 23, 2017 at 05:51:38PM +0000, Rogozhkin, Dmitry V wrote: > > > > The above command tries to add an event 'i915/rcs0-busy/' to a task. How > > > are i915 resource associated to any one particular task? > > > > Currently in no way, they are global. > > Right. So no per DRM context things. Can you have multiple DRM contexts > per task? If so that would make things slightly tricky when you get away > from !global counters. Just to be sure we are on the same page: under task we understand the process which is being monitored with the perf: "perf stat -e <ev> task.sh"? Yes, each process may have few DRM contexts, so we are in a tricky space:). If we will decide to support per-task counters in the future, would it be possible to preserve global mode providing end-user a choice: monitor per-process or globally? > > > > Is there a unique i915 resource for each task? If not, I don't see how > > > per-task event can ever work as expected. > > > > This depends on what you mean under "expected"? I see 2 variants: > > 1. Either this command line should return correct metric values > > 2. This command line should error out > > > Right now i915 PMU produces global metric, thus, I think 2nd variant is > > true. Which I think is achievable if PMU is registered with > > perf_invalid_context. > > Agreed, and yes, perf_invalid_context is right for uncore stuff and will > result in refusal to create per-task counters. _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
