@@ -590,6 +590,7 @@ struct x86_pmu {
pebs_active :1,
pebs_broken :1;
int pebs_record_size;
+ int pebs_buffer_size;
void (*drain_pebs)(struct pt_regs *regs);
struct event_constraint *pebs_constraints;
void (*pebs_aliases)(struct perf_event *event);
@@ -256,7 +256,7 @@ static int alloc_pebs_buffer(int cpu)
if (!x86_pmu.pebs)
return 0;
- buffer = kzalloc_node(PEBS_BUFFER_SIZE, GFP_KERNEL, node);
+ buffer = kzalloc_node(x86_pmu.pebs_buffer_size, GFP_KERNEL, node);
if (unlikely(!buffer))
return -ENOMEM;
@@ -273,7 +273,7 @@ static int alloc_pebs_buffer(int cpu)
per_cpu(insn_buffer, cpu) = ibuffer;
}
- max = PEBS_BUFFER_SIZE / x86_pmu.pebs_record_size;
+ max = x86_pmu.pebs_buffer_size / x86_pmu.pebs_record_size;
ds->pebs_buffer_base = (u64)(unsigned long)buffer;
ds->pebs_index = ds->pebs_buffer_base;
@@ -1229,6 +1229,7 @@ void __init intel_ds_init(void)
x86_pmu.bts = boot_cpu_has(X86_FEATURE_BTS);
x86_pmu.pebs = boot_cpu_has(X86_FEATURE_PEBS);
+ x86_pmu.pebs_buffer_size = PEBS_BUFFER_SIZE;
if (x86_pmu.pebs) {
char pebs_type = x86_pmu.intel_cap.pebs_trap ? '+' : '-';
int format = x86_pmu.intel_cap.pebs_format;
@@ -1237,6 +1238,14 @@ void __init intel_ds_init(void)
case 0:
printk(KERN_CONT "PEBS fmt0%c, ", pebs_type);
x86_pmu.pebs_record_size = sizeof(struct pebs_record_core);
+ /*
+ * Using >PAGE_SIZE buffers makes the WRMSR to
+ * PERF_GLOBAL_CTRL in intel_pmu_enable_all()
+ * mysteriously hang on Core2.
+ *
+ * As a workaround, we don't do this.
+ */
+ x86_pmu.pebs_buffer_size = PAGE_SIZE;
x86_pmu.drain_pebs = intel_pmu_drain_pebs_core;
break;