diff --git a/include/proto/activity.h b/include/proto/activity.h
index 922f493..dd78344 100644
--- a/include/proto/activity.h
+++ b/include/proto/activity.h
@@ -29,7 +29,10 @@
 #include <proto/freq_ctr.h>
 
 /* bit fields for "profiling" */
-#define HA_PROF_TASKS       0x00000001     /* enable per-task CPU profiling */
+#define HA_PROF_TASKS_OFF   0x00000000     /* per-task CPU profiling forced disabled */
+#define HA_PROF_TASKS_AUTO  0x00000001     /* per-task CPU profiling automatic */
+#define HA_PROF_TASKS_ON    0x00000002     /* per-task CPU profiling forced enabled */
+#define HA_PROF_TASKS_MASK  0x00000003     /* per-task CPU profiling mask */
 
 extern unsigned int profiling;
 extern unsigned long task_profiling_mask;
@@ -49,6 +52,13 @@
 	uint64_t new_cpu_time;
 	int64_t stolen;
 	uint32_t run_time;
+	uint32_t up, down;
+
+	/* 1 millisecond per loop on average over last 1024 iterations is
+	 * enough to turn on profiling.
+	 */
+	up = 1000;
+	down = up * 99 / 100;
 
 	new_cpu_time   = now_cpu_time();
 	new_mono_time  = now_mono_time();
@@ -69,12 +79,22 @@
 	run_time = (before_poll.tv_sec - after_poll.tv_sec) * 1000000U + (before_poll.tv_usec - after_poll.tv_usec);
 	swrate_add(&activity[tid].avg_loop_us, TIME_STATS_SAMPLES, run_time);
 
+	/* reaching the "up" threshold on average switches profiling to "on"
+	 * when automatic, and going back below the "down" threshold switches
+	 * to off.
+	 */
 	if (!(task_profiling_mask & tid_bit)) {
-		if (unlikely(profiling & HA_PROF_TASKS))
-			_HA_ATOMIC_OR(&task_profiling_mask, tid_bit);
+		if (unlikely((profiling & HA_PROF_TASKS_MASK) == HA_PROF_TASKS_ON ||
+			     ((profiling & HA_PROF_TASKS_MASK) == HA_PROF_TASKS_AUTO && run_time >= up))) {
+			if (swrate_avg(activity[tid].avg_loop_us, TIME_STATS_SAMPLES) >= up)
+				_HA_ATOMIC_OR(&task_profiling_mask, tid_bit);
+		}
 	} else {
-		if (unlikely(!(profiling & HA_PROF_TASKS)))
-			_HA_ATOMIC_AND(&task_profiling_mask, ~tid_bit);
+		if (unlikely((profiling & HA_PROF_TASKS_MASK) == HA_PROF_TASKS_OFF ||
+			     ((profiling & HA_PROF_TASKS_MASK) == HA_PROF_TASKS_AUTO && run_time <= down))) {
+			if (swrate_avg(activity[tid].avg_loop_us, TIME_STATS_SAMPLES) <= down)
+				_HA_ATOMIC_AND(&task_profiling_mask, ~tid_bit);
+		}
 	}
 }