+static void process_nice_level(void) {
+#ifdef HAVE_NICE
+ int nice_level = (int)config_get_number(CONFIG_SECTION_GLOBAL, "process nice level", 19);
+ if(nice(nice_level) == -1) error("Cannot set netdata CPU nice level to %d.", nice_level);
+ else debug(D_SYSTEM, "Set netdata nice level to %d.", nice_level);
+#endif // HAVE_NICE
+};
+
+#ifdef HAVE_SCHED_SETSCHEDULER
+
+#define SCHED_FLAG_NONE 0x00
+#define SCHED_FLAG_PRIORITY_CONFIGURABLE 0x01 // the priority is user configurable
+#define SCHED_FLAG_KEEP_AS_IS 0x04 // do not attempt to set policy, priority or nice()
+#define SCHED_FLAG_USE_NICE 0x08 // use nice() after setting this policy
+
+struct sched_def {
+ char *name;
+ int policy;
+ int priority;
+ uint8_t flags;
+} scheduler_defaults[] = {
+
+ // the order of array members is important!
+ // the first defined is the default used by netdata
+
+ // the available members are important too!
+ // these are all the possible scheduling policies supported by netdata
+
+#ifdef SCHED_IDLE
+ { "idle", SCHED_IDLE, 0, SCHED_FLAG_NONE },
+#endif
+
+#ifdef SCHED_OTHER
+ { "nice", SCHED_OTHER, 0, SCHED_FLAG_USE_NICE },
+ { "other", SCHED_OTHER, 0, SCHED_FLAG_USE_NICE },
+#endif
+
+#ifdef SCHED_RR
+ { "rr", SCHED_RR, 0, SCHED_FLAG_PRIORITY_CONFIGURABLE },
+#endif
+
+#ifdef SCHED_FIFO
+ { "fifo", SCHED_FIFO, 0, SCHED_FLAG_PRIORITY_CONFIGURABLE },
+#endif
+
+#ifdef SCHED_BATCH
+ { "batch", SCHED_BATCH, 0, SCHED_FLAG_USE_NICE },
+#endif
+
+ // do not change the scheduling priority
+ { "keep", 0, 0, SCHED_FLAG_KEEP_AS_IS },
+ { "none", 0, 0, SCHED_FLAG_KEEP_AS_IS },
+
+ // array termination
+ { NULL, 0, 0, 0 }
+};
+
+static void sched_setscheduler_set(void) {
+
+ if(scheduler_defaults[0].name) {
+ const char *name = scheduler_defaults[0].name;
+ int policy = scheduler_defaults[0].policy, priority = scheduler_defaults[0].priority;
+ uint8_t flags = scheduler_defaults[0].flags;
+ int found = 0;
+
+ // read the configuration
+ name = config_get(CONFIG_SECTION_GLOBAL, "process scheduling policy", name);
+ int i;
+ for(i = 0 ; scheduler_defaults[i].name ; i++) {
+ if(!strcmp(name, scheduler_defaults[i].name)) {
+ found = 1;
+ priority = scheduler_defaults[i].priority;
+ flags = scheduler_defaults[i].flags;
+
+ if(flags & SCHED_FLAG_KEEP_AS_IS)
+ return;
+
+ if(flags & SCHED_FLAG_PRIORITY_CONFIGURABLE)
+ priority = (int)config_get_number(CONFIG_SECTION_GLOBAL, "process scheduling priority", priority);
+
+#ifdef HAVE_SCHED_GET_PRIORITY_MIN
+ if(priority < sched_get_priority_min(policy)) {
+ error("scheduler %s priority %d is below the minimum %d. Using the minimum.", name, priority, sched_get_priority_min(policy));
+ priority = sched_get_priority_min(policy);
+ }
+#endif
+#ifdef HAVE_SCHED_GET_PRIORITY_MAX
+ if(priority > sched_get_priority_max(policy)) {
+ error("scheduler %s priority %d is above the maximum %d. Using the maximum.", name, priority, sched_get_priority_max(policy));
+ priority = sched_get_priority_max(policy);
+ }
+#endif
+ break;
+ }
+ }
+
+ if(!found) {
+ error("Unknown scheduling policy %s - falling back to nice()", name);
+ goto fallback;
+ }
+
+ const struct sched_param param = {
+ .sched_priority = priority
+ };