On Fri, Jul 24, 2020 at 03:19:06PM +0200, pet...@infradead.org wrote: > On Thu, Jul 23, 2020 at 10:11:11AM -0700, kan.li...@linux.intel.com wrote: > > @@ -3375,6 +3428,72 @@ static int intel_pmu_hw_config(struct perf_event > > *event) > > if (event->attr.type != PERF_TYPE_RAW) > > return 0; > > > > + /* > > + * Config Topdown slots and metric events > > + * > > + * The slots event on Fixed Counter 3 can support sampling, > > + * which will be handled normally in x86_perf_event_update(). > > + * > > + * The metric events don't support sampling. > > + * > > + * For counting, topdown slots and metric events will be > > + * handled specially for event update. > > + * A flag PERF_X86_EVENT_TOPDOWN is applied for the case. > > + */ > > + if (x86_pmu.intel_cap.perf_metrics && is_topdown_event(event)) { > > + if (is_metric_event(event)) { > > + struct perf_event *leader = event->group_leader; > > + struct perf_event *sibling; > > + > > + /* The metric events don't support sampling. */ > > + if (is_sampling_event(event)) > > + return -EINVAL; > > + > > + /* The metric events cannot be a group leader. */ > > + if (leader == event) > > + return -EINVAL; > > + > > + /* > > + * The slots event cannot be the leader of a topdown > > + * sample-read group, e.g., {slots, topdown-retiring}:S > > + */ > > + if (is_slots_event(leader) && is_sampling_event(leader)) > > + return -EINVAL; > > This has nothing to do with sample-read; SLOTS cannot be sampling when > coupled with the METRIC stuff because hardware is daft. > > And you can have SAMPLE_READ on non-leader events just fine. > > > + > > + /* > > + * The slots event must be before the metric events, > > + * because we only update the values of a topdown > > + * group once with the slots event. > > + */ > > + if (!is_slots_event(leader)) { > > + for_each_sibling_event(sibling, leader) { > > + if (is_slots_event(sibling)) > > + break; > > + if (is_metric_event(sibling)) > > + return -EINVAL; > > + } > > + } > > Per the SIBLING patch this then wants to be: > > if (!is_slots_event(leader)) > return -EINVAL; > > event->event_caps |= PERF_EV_CAP_SIBLING. > /* > * Only once we have a METRICs sibling to we > * need TopDown magic. > */ > leader->hw.flags |= PERF_X86_EVENT_TOPDOWN; > > + } > > + > > + if (!is_sampling_event(event)) { > > + if (event->attr.config1 != 0) > > + return -EINVAL; > > How does this depend on sampling? > > > + /* > > + * The TopDown metrics events and slots event don't > > + * support any filters. > > + */ > > + if (event->attr.config & X86_ALL_EVENT_FLAGS) > > + return -EINVAL; > > That seems independent of sampling too. Even a sampling SLOTS shouldn't > be having any of those afaict. > > > + > > + event->hw.flags |= PERF_X86_EVENT_TOPDOWN; > > This is confusing too, a !sampling SLOTS event without METRIC siblings > shouldn't have this set, right? So arguably, this should be like above. > > > + > > + event->event_caps |= PERF_EV_CAP_COEXIST; > > + > > + if (is_metric_event(event)) > > + event->hw.flags &= > > ~PERF_X86_EVENT_RDPMC_ALLOWED; > > This too seems like something that should be in the is_metric_event() > branch above. > > > + } > > + } > > + > > if (!(event->attr.config & ARCH_PERFMON_EVENTSEL_ANY)) > > return 0; > >
FWIW, I pushed out a branch with all these changes in: git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git perf/metric Just to get it some build love, if you want it differently, I'm happy to throw it all out again.