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Diffstat (limited to 'arch/x86/events/amd/core.c')
-rw-r--r--arch/x86/events/amd/core.c21
1 files changed, 18 insertions, 3 deletions
diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c
index 049ada8d..86a9bec 100644
--- a/arch/x86/events/amd/core.c
+++ b/arch/x86/events/amd/core.c
@@ -369,7 +369,7 @@ static int amd_pmu_cpu_prepare(int cpu)
WARN_ON_ONCE(cpuc->amd_nb);
- if (boot_cpu_data.x86_max_cores < 2)
+ if (!x86_pmu.amd_nb_constraints)
return NOTIFY_OK;
cpuc->amd_nb = amd_alloc_nb(cpu);
@@ -388,7 +388,7 @@ static void amd_pmu_cpu_starting(int cpu)
cpuc->perf_ctr_virt_mask = AMD64_EVENTSEL_HOSTONLY;
- if (boot_cpu_data.x86_max_cores < 2)
+ if (!x86_pmu.amd_nb_constraints)
return;
nb_id = amd_get_nb_id(cpu);
@@ -414,7 +414,7 @@ static void amd_pmu_cpu_dead(int cpu)
{
struct cpu_hw_events *cpuhw;
- if (boot_cpu_data.x86_max_cores < 2)
+ if (!x86_pmu.amd_nb_constraints)
return;
cpuhw = &per_cpu(cpu_hw_events, cpu);
@@ -648,6 +648,8 @@ static __initconst const struct x86_pmu amd_pmu = {
.cpu_prepare = amd_pmu_cpu_prepare,
.cpu_starting = amd_pmu_cpu_starting,
.cpu_dead = amd_pmu_cpu_dead,
+
+ .amd_nb_constraints = 1,
};
static int __init amd_core_pmu_init(void)
@@ -674,6 +676,11 @@ static int __init amd_core_pmu_init(void)
x86_pmu.eventsel = MSR_F15H_PERF_CTL;
x86_pmu.perfctr = MSR_F15H_PERF_CTR;
x86_pmu.num_counters = AMD64_NUM_COUNTERS_CORE;
+ /*
+ * AMD Core perfctr has separate MSRs for the NB events, see
+ * the amd/uncore.c driver.
+ */
+ x86_pmu.amd_nb_constraints = 0;
pr_cont("core perfctr, ");
return 0;
@@ -693,6 +700,14 @@ __init int amd_pmu_init(void)
if (ret)
return ret;
+ if (num_possible_cpus() == 1) {
+ /*
+ * No point in allocating data structures to serialize
+ * against other CPUs, when there is only the one CPU.
+ */
+ x86_pmu.amd_nb_constraints = 0;
+ }
+
/* Events are common for all AMDs */
memcpy(hw_cache_event_ids, amd_hw_cache_event_ids,
sizeof(hw_cache_event_ids));
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