diff --git a/src/activity.c b/src/activity.c
index 764613f..8ccff23 100644
--- a/src/activity.c
+++ b/src/activity.c
@@ -21,8 +21,8 @@
 
 
 /* bit field of profiling options. Beware, may be modified at runtime! */
-unsigned int profiling = HA_PROF_TASKS_AOFF;
-unsigned long task_profiling_mask = 0;
+unsigned int profiling __read_mostly = HA_PROF_TASKS_AOFF;
+unsigned long task_profiling_mask __read_mostly = 0;
 
 /* One struct per thread containing all collected measurements */
 struct activity activity[MAX_THREADS] __attribute__((aligned(64))) = { };