return(0);
}
-void oom_score_adj(int score) {
+static void oom_score_adj(void) {
+ int score = (int)config_get_number("global", "OOM score", 1000);
+
int done = 0;
int fd = open("/proc/self/oom_score_adj", O_WRONLY);
if(fd != -1) {
char buf[10 + 1];
ssize_t len = snprintfz(buf, 10, "%d", score);
- if(write(fd, buf, len) == len) done = 1;
+ if(len > 0 && write(fd, buf, (size_t)len) == len) done = 1;
close(fd);
}
debug(D_SYSTEM, "Adjusted my Out-Of-Memory score to %d.", score);
}
-int sched_setscheduler_idle(void) {
+static void process_nice_level(void) {
+#ifdef HAVE_NICE
+ int nice_level = (int)config_get_number("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
- const struct sched_param param = {
- .sched_priority = 0
- };
+ { "idle", SCHED_IDLE, 0, SCHED_FLAG_NONE },
+#endif
- int i = sched_setscheduler(0, SCHED_IDLE, ¶m);
- if(i != 0)
- error("Cannot adjust my scheduling priority to IDLE.");
- else
- debug(D_SYSTEM, "Adjusted my scheduling priority to IDLE.");
+#ifdef SCHED_OTHER
+ { "nice", SCHED_OTHER, 0, SCHED_FLAG_USE_NICE },
+ { "other", SCHED_OTHER, 0, SCHED_FLAG_USE_NICE },
+#endif
- return i;
-#else
- return -1;
+#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("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("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
+ };
+
+ i = sched_setscheduler(0, policy, ¶m);
+ if(i != 0) {
+ error("Cannot adjust netdata scheduling policy to %s (%d), with priority %d. Falling back to nice", name, policy, priority);
+ }
+ else {
+ debug(D_SYSTEM, "Adjusted netdata scheduling policy to %s (%d), with priority %d.", name, policy, priority);
+ if(!(flags & SCHED_FLAG_USE_NICE))
+ return;
+ }
+ }
+
+fallback:
+ process_nice_level();
}
+#else
+static void sched_setscheduler_set(void) {
+ process_nice_level();
+}
+#endif
int become_daemon(int dont_fork, const char *user)
{
umask(0007);
// adjust my Out-Of-Memory score
- oom_score_adj(1000);
+ oom_score_adj();
// never become a problem
- if(sched_setscheduler_idle() != 0) {
- if(nice(19) == -1) error("Cannot lower my CPU priority.");
- else debug(D_SYSTEM, "Set my nice value to 19.");
- }
+ sched_setscheduler_set();
if(user && *user) {
if(become_user(user, pidfd) != 0) {