On Tue, Jul 14, 2015 at 08:01:54PM -0700, Sukadev Bhattiprolu wrote: > +/* > + * Use the transaction interface to read the group of events in @leader. > + * PMUs like the 24x7 counters in Power, can use this to queue the events > + * in the ->read() operation and perform the actual read in ->commit_txn. > + * > + * Other PMUs can ignore the ->start_txn and ->commit_txn and read each > + * PMU directly in the ->read() operation. > + */ > +static int perf_event_read_group(struct perf_event *leader) > +{ > + int ret; > + struct perf_event *sub; > + struct pmu *pmu; > + > + pmu = leader->pmu; > + > + pmu->start_txn(pmu, PERF_PMU_TXN_READ); > + > + perf_event_read(leader); There should be a lockdep assert with that list iteration. > + list_for_each_entry(sub, &leader->sibling_list, group_entry) > + perf_event_read(sub); > + > + ret = pmu->commit_txn(pmu); > + > + return ret; > +} -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html