From: Yicong Yang <yangyicong@hisilicon.com> driver inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IC0GTV ---------------------------------------------------------------------- There are two type of PMUs supported currently: 1) PMUs locate on SCCL (Super CPU Cluster [1]), associated with certain CCL (CPU cluster [1])(e.g. L3C PMU) or not (e.g. DDRC PMU) 2) PMUs locate on the SICL (Super IO Cluster [1]), which has no association with certain CPU topology (e.g. CPA PMU) Currently the associated CPUs of the PMU is detected in the cpuhp online callback as below: - for type 1) the CPUs match PMU's sccl_id and ccl_id - for type 2) PMU's sccl_id is -1 and all online CPUs will be associated Since uncore PMUs are not bound to certain CPU context and event could be counting started by any online CPU, the associated CPUs are just a preference. Below disadvantages are observed in current implementation: - the PMU cannot be used if its associated CPUs are offline - SICL PMUs are associated to all the online CPUs implicitly without the consideration of locality So refactor the way we detect the associated CPUs in below aspects: - add a clear definition of hisi_pmu::associated_cpus - initialize hisi_pmu::on_cpu based on locality if no associated CPU found, otherwise update it from associated CPUs - drop the detection with a sccl_id of -1 for SICL PMUs [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu... Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> --- drivers/perf/hisilicon/hisi_uncore_pmu.c | 22 +++++++++++++++------- drivers/perf/hisilicon/hisi_uncore_pmu.h | 6 +++++- 2 files changed, 20 insertions(+), 8 deletions(-) diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pmu.c index 8e35ea0a71b0..2d101d373212 100644 --- a/drivers/perf/hisilicon/hisi_uncore_pmu.c +++ b/drivers/perf/hisilicon/hisi_uncore_pmu.c @@ -460,10 +460,6 @@ static bool hisi_pmu_cpu_is_associated_pmu(struct hisi_pmu *hisi_pmu) { int sccl_id, ccl_id; - /* If SCCL_ID is -1, the PMU is in a SICL and has no CPU affinity */ - if (hisi_pmu->sccl_id == -1) - return true; - if (hisi_pmu->ccl_id == -1) { /* If CCL_ID is -1, the PMU only shares the same SCCL */ hisi_read_sccl_and_ccl_id(&sccl_id, NULL); @@ -481,13 +477,25 @@ int hisi_uncore_pmu_online_cpu(unsigned int cpu, struct hlist_node *node) struct hisi_pmu *hisi_pmu = hlist_entry_safe(node, struct hisi_pmu, node); - if (!hisi_pmu_cpu_is_associated_pmu(hisi_pmu)) + /* + * If the CPU is not associated to PMU, initialize the hisi_pmu->on_cpu + * based on the locality if it hasn't been initialized yet. For PMUs + * do have associated CPUs, it'll be updated later. + */ + if (!hisi_pmu_cpu_is_associated_pmu(hisi_pmu)) { + if (hisi_pmu->on_cpu != -1) + return 0; + + hisi_pmu->on_cpu = cpumask_local_spread(0, dev_to_node(hisi_pmu->dev)); + WARN_ON(irq_set_affinity(hisi_pmu->irq, cpumask_of(cpu))); return 0; + } cpumask_set_cpu(cpu, &hisi_pmu->associated_cpus); - /* If another CPU is already managing this PMU, simply return. */ - if (hisi_pmu->on_cpu != -1) + /* If another associated CPU is already managing this PMU, simply return. */ + if (hisi_pmu->on_cpu != -1 && + cpumask_test_cpu(hisi_pmu->on_cpu, &hisi_pmu->associated_cpus)) return 0; /* Use this CPU in cpumask for event counting */ diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.h b/drivers/perf/hisilicon/hisi_uncore_pmu.h index 92402aa69d70..0719dac40434 100644 --- a/drivers/perf/hisilicon/hisi_uncore_pmu.h +++ b/drivers/perf/hisilicon/hisi_uncore_pmu.h @@ -87,7 +87,11 @@ struct hisi_pmu { const struct hisi_uncore_ops *ops; const struct hisi_pmu_dev_info *dev_info; struct hisi_pmu_hwevents pmu_events; - /* associated_cpus: All CPUs associated with the PMU */ + /* + * CPUs associated to the PMU and are preferred to use for counting. + * Could be empty if PMU has no association (e.g. PMU on SICL), in + * which case any online CPU will be used. + */ cpumask_t associated_cpus; /* CPU used for counting */ int on_cpu; -- 2.33.0