+/* sample should include system samplers */
+#define SAMPLE_FLAG_SYSTEM (1U << 5)
+/* sample should not include non-system samplers */
+#define SAMPLE_FLAG_ONLY_SYSTEM (1U << 6)
+/* sample should only include task samplers */
+#define SAMPLE_FLAG_TASK_ONLY (1U << 7)
+/* sample should only include thread samplers */
+#define SAMPLE_FLAG_THREAD_ONLY (1U << 8)