diff options
author | Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> | 2012-09-25 17:26:51 +0100 |
---|---|---|
committer | Jon Medhurst <tixy@linaro.org> | 2014-03-31 13:57:55 +0100 |
commit | 7b12ebf38f57a175e1068e986b5d58e7225f1817 (patch) | |
tree | 78e24bb50acce4521cfb6d9d31a912adfd121ee2 /arch/arm/kernel/perf_event.c | |
parent | be596295d8f906d7626508ad8f9f12687feebde2 (diff) |
ARM: perf: set cpu affinity to support multiple PMUs
In a system with multiple heterogeneous CPU PMUs and each PMUs can handle
events on a subset of CPUs, probably belonging a the same cluster.
This patch introduces a cpumask to track which CPUs each PMU supports.
It also updates armpmu_event_init to reject cpu-specific events being
initialised for unsupported CPUs. Since process-specific events can be
initialised for all the CPU PMUs,armpmu_start/stop/add are modified to
prevent from being added on unsupported CPUs.
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Diffstat (limited to 'arch/arm/kernel/perf_event.c')
-rw-r--r-- | arch/arm/kernel/perf_event.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index f37b57cca32..42059a54a9c 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -12,6 +12,7 @@ */ #define pr_fmt(fmt) "hw perfevents: " fmt +#include <linux/cpumask.h> #include <linux/kernel.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> @@ -162,6 +163,8 @@ armpmu_stop(struct perf_event *event, int flags) struct arm_pmu *armpmu = to_arm_pmu(event->pmu); struct hw_perf_event *hwc = &event->hw; + if (!cpumask_test_cpu(smp_processor_id(), &armpmu->valid_cpus)) + return; /* * ARM pmu always has to update the counter, so ignore * PERF_EF_UPDATE, see comments in armpmu_start(). @@ -178,6 +181,8 @@ static void armpmu_start(struct perf_event *event, int flags) struct arm_pmu *armpmu = to_arm_pmu(event->pmu); struct hw_perf_event *hwc = &event->hw; + if (!cpumask_test_cpu(smp_processor_id(), &armpmu->valid_cpus)) + return; /* * ARM pmu always has to reprogram the period, so ignore * PERF_EF_RELOAD, see the comment below. @@ -205,6 +210,9 @@ armpmu_del(struct perf_event *event, int flags) struct hw_perf_event *hwc = &event->hw; int idx = hwc->idx; + if (!cpumask_test_cpu(smp_processor_id(), &armpmu->valid_cpus)) + return; + armpmu_stop(event, PERF_EF_UPDATE); hw_events->events[idx] = NULL; clear_bit(idx, hw_events->used_mask); @@ -221,6 +229,10 @@ armpmu_add(struct perf_event *event, int flags) int idx; int err = 0; + /* An event following a process won't be stopped earlier */ + if (!cpumask_test_cpu(smp_processor_id(), &armpmu->valid_cpus)) + return 0; + perf_pmu_disable(event->pmu); /* If we don't have a space for the counter then finish early. */ @@ -422,6 +434,10 @@ static int armpmu_event_init(struct perf_event *event) int err = 0; atomic_t *active_events = &armpmu->active_events; + if (event->cpu != -1 && + !cpumask_test_cpu(event->cpu, &armpmu->valid_cpus)) + return -ENOENT; + /* does not support taken branch sampling */ if (has_branch_stack(event)) return -EOPNOTSUPP; |