From: Yan, Zheng Date: Thu, 4 Sep 2014 23:08:27 +0000 (-0700) Subject: perf/x86/intel/uncore: Register the PMU only if the uncore pci device exists X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=513d793e5fe138d779ad6c532cd20c289a6897fc;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git perf/x86/intel/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 Signed-off-by: Peter Zijlstra (Intel) Cc: eranian@google.com Link: http://lkml.kernel.org/r/1409872109-31645-3-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c index 2b0fa02268b7..42d00e53175d 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c @@ -793,6 +793,7 @@ 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 = uncore_pcibus_to_physid[pdev->bus->number]; if (phys_id < 0) @@ -827,9 +828,13 @@ 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; } @@ -838,6 +843,7 @@ 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 = uncore_pcibus_to_physid[pdev->bus->number]; + bool last_box = false; box = pci_get_drvdata(pdev); if (!box) { @@ -859,6 +865,8 @@ 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) { @@ -870,6 +878,9 @@ 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) @@ -1221,14 +1232,6 @@ static int __init uncore_pmus_register(void) } } - for (i = 0; uncore_pci_uncores[i]; i++) { - type = uncore_pci_uncores[i]; - for (j = 0; j < type->num_boxes; j++) { - pmu = &type->pmus[j]; - uncore_pmu_register(pmu); - } - } - return 0; }