From 26eadfb58bfb130254c04bff30fe2e2db775fd08 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Wed, 20 Aug 2014 09:50:58 +0800 Subject: [PATCH 2/2] perf/x86/uncore: register the PMU only if the uncore pci device exists Current code registers PMUs for all possible uncore pci devices. This is not good because, on some machines, one or more uncore pci devices can be missing. The missing pci device make corresponding PMU unusable. Register the PMU only if the uncore device exists. Signed-off-by: Yan, Zheng Signed-off-by: Andi Kleen Conflicts: arch/x86/kernel/cpu/perf_event_intel_uncore.c --- arch/x86/kernel/cpu/perf_event_intel_uncore.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c index f538bcf..ab7c597 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c @@ -4382,6 +4382,7 @@ static int uncore_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id struct intel_uncore_box *box; struct intel_uncore_type *type; int phys_id; + bool first_box = false; phys_id = pcibus_to_physid[pdev->bus->number]; if (phys_id < 0) @@ -4415,9 +4416,13 @@ static int uncore_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id pci_set_drvdata(pdev, box); raw_spin_lock(&uncore_box_lock); + if (list_empty(&pmu->box_list)) + first_box = true; list_add_tail(&box->list, &pmu->box_list); raw_spin_unlock(&uncore_box_lock); + if (first_box) + uncore_pmu_register(pmu); return 0; } @@ -4426,6 +4431,7 @@ static void uncore_pci_remove(struct pci_dev *pdev) struct intel_uncore_box *box = pci_get_drvdata(pdev); struct intel_uncore_pmu *pmu; int i, cpu, phys_id = pcibus_to_physid[pdev->bus->number]; + bool last_box = false; box = pci_get_drvdata(pdev); if (!box) { @@ -4447,6 +4453,8 @@ static void uncore_pci_remove(struct pci_dev *pdev) raw_spin_lock(&uncore_box_lock); list_del(&box->list); + if (list_empty(&pmu->box_list)) + last_box = true; raw_spin_unlock(&uncore_box_lock); for_each_possible_cpu(cpu) { @@ -4458,6 +4466,9 @@ static void uncore_pci_remove(struct pci_dev *pdev) WARN_ON_ONCE(atomic_read(&box->refcnt) != 1); kfree(box); + + if (last_box) + perf_pmu_unregister(&pmu->pmu); } static int __init uncore_pci_init(void) @@ -4838,14 +4849,6 @@ static int __init uncore_pmus_register(void) } } - for (i = 0; pci_uncores[i]; i++) { - type = pci_uncores[i]; - for (j = 0; j < type->num_boxes; j++) { - pmu = &type->pmus[j]; - uncore_pmu_register(pmu); - } - } - return 0; } -- 1.8.4.5