On Wed, May 12, 2021 at 10:08:21PM +0530, Kajol Jain wrote: > +static void nvdimm_pmu_read(struct perf_event *event) > +{ > + struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu); > + > + /* jump to arch/platform specific callbacks if any */ > + if (nd_pmu && nd_pmu->read) > + nd_pmu->read(event, nd_pmu->dev); > +} > + > +static void nvdimm_pmu_del(struct perf_event *event, int flags) > +{ > + struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu); > + > + /* jump to arch/platform specific callbacks if any */ > + if (nd_pmu && nd_pmu->del) > + nd_pmu->del(event, flags, nd_pmu->dev); > +} > + > +static int nvdimm_pmu_add(struct perf_event *event, int flags) > +{ > + struct nvdimm_pmu *nd_pmu = to_nvdimm_pmu(event->pmu); > + > + if (flags & PERF_EF_START) > + /* jump to arch/platform specific callbacks if any */ > + if (nd_pmu && nd_pmu->add) > + return nd_pmu->add(event, flags, nd_pmu->dev); > + return 0; > +}
What's the value add here? Why can't you directly set driver pointers? I also don't really believe ->{add,del,read} can be optional and still have a sane driver.