fix(driver/bpf): decrease limits to support some GKE env

Signed-off-by: Andrea Terzolo <andreaterzolo3@gmail.com>

driver/bpf/fillers.h

@@ -5044,10 +5044,13 @@ FILLER(sched_drop, false)
 	return bpf_push_u32_to_ring(data, data->settings->sampling_ratio);
 }
 
-/* In this kernel version the instruction limit was bumped to 1000000 */
+/* In this kernel version the instruction limit was bumped to 1000000.
+ * We use these 2 values because they are the minimum required to run our eBPF probe
+ * on some GKE environments. See https://github.com/falcosecurity/libs/issues/1639
+ */
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5, 2, 0))
-#define MAX_THREADS_GROUPS 30
-#define MAX_HIERARCHY_TRAVERSE 60
+#define MAX_THREADS_GROUPS 25
+#define MAX_HIERARCHY_TRAVERSE 35
 #else
 /* We need to find the right calibration here. On kernel 4.14 the limit
  * seems to be MAX_THREADS_GROUPS*MAX_HIERARCHY_TRAVERSE <= 100