Re: [RFC 1/4] drivers/nvdimm: Add perf interface to expose nvdimm performance stats
flat view
From: Peter Zijlstra <peterz@infradead.org>
Date: 2021-05-12 19:36:47
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On Wed, May 12, 2021 at 10:08:21PM +0530, Kajol Jain wrote:
quoted hunk ↗ jump to hunk
+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.