2 files changed, 23 insertions, 7 deletions

diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h
index 66017028dcb3..add13c8624b7 100644
--- a/include/linux/irq_work.h
+++ b/include/linux/irq_work.h
@@ -30,6 +30,8 @@ void init_irq_work(struct irq_work *work, void (*func)(struct irq_work *))
         work->func = func;
 }
 
+#define DEFINE_IRQ_WORK(name, _f) struct irq_work name = { .func = (_f), }
+
 void irq_work_queue(struct irq_work *work);
 void irq_work_run(void);
 void irq_work_sync(struct irq_work *work);
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 56003c6edfd3..2067cbb378eb 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -231,11 +231,29 @@ int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
 #define NR_ACCUMULATED_SAMPLES 128
 static DEFINE_PER_CPU(u64, running_sample_length);
 
-void perf_sample_event_took(u64 sample_len_ns)
+static void perf_duration_warn(struct irq_work *w)
 {
+        u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns);
         u64 avg_local_sample_len;
         u64 local_samples_len;
+
+        local_samples_len = __get_cpu_var(running_sample_length);
+        avg_local_sample_len = local_samples_len/NR_ACCUMULATED_SAMPLES;
+
+        printk_ratelimited(KERN_WARNING
+                        "perf interrupt took too long (%lld > %lld), lowering "
+                        "kernel.perf_event_max_sample_rate to %d\n",
+                        avg_local_sample_len, allowed_ns,
+                        sysctl_perf_event_sample_rate);
+}
+
+static DEFINE_IRQ_WORK(perf_duration_work, perf_duration_warn);
+
+void perf_sample_event_took(u64 sample_len_ns)
+{
         u64 allowed_ns = ACCESS_ONCE(perf_sample_allowed_ns);
+        u64 avg_local_sample_len;
+        u64 local_samples_len;
 
         if (allowed_ns == 0)
                 return;
@@ -263,13 +281,9 @@ void perf_sample_event_took(u64 sample_len_ns)
         sysctl_perf_event_sample_rate = max_samples_per_tick * HZ;
         perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
 
-        printk_ratelimited(KERN_WARNING
-                        "perf samples too long (%lld > %lld), lowering "
-                        "kernel.perf_event_max_sample_rate to %d\n",
-                        avg_local_sample_len, allowed_ns,
-                        sysctl_perf_event_sample_rate);
-
         update_perf_cpu_limits();
+
+        irq_work_queue(&perf_duration_work);
 }
 
 static atomic64_t perf_event_id;