1 files changed, 130 insertions, 24 deletions

diff --git a/src/daemon.c b/src/daemon.c
index 4fd8ca5e5..42b04c401 100644
--- a/src/daemon.c
+++ b/src/daemon.c
@@ -27,7 +27,7 @@ void sig_handler_save(int signo)
     if(signo) {
         error_log_limit_unlimited();
         info("Received signal %d to save the database...", signo);
-        rrdset_save_all();
+        rrdhost_save_all();
         error_log_limit_reset();
     }
 }
@@ -84,8 +84,8 @@ int become_user(const char *username, int pid_fd)
     uid_t uid = pw->pw_uid;
     gid_t gid = pw->pw_gid;
 
-    create_needed_dir(CACHE_DIR, uid, gid);
-    create_needed_dir(VARLIB_DIR, uid, gid);
+    create_needed_dir(netdata_configured_cache_dir, uid, gid);
+    create_needed_dir(netdata_configured_varlib_dir, uid, gid);
 
     if(pidfile[0]) {
         if(chown(pidfile, uid, gid) == -1)
@@ -155,13 +155,15 @@ int become_user(const char *username, int pid_fd)
     return(0);
 }
 
-void oom_score_adj(int score) {
+static void oom_score_adj(void) {
+    int score = (int)config_get_number(CONFIG_SECTION_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);
     }
 
@@ -171,23 +173,130 @@ void oom_score_adj(int score) {
         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(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
-    const struct sched_param param = {
-        .sched_priority = 0
-    };
+        { "idle", SCHED_IDLE, 0, SCHED_FLAG_NONE },
+#endif
 
-    int i = sched_setscheduler(0, SCHED_IDLE, &param);
-    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(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
+        };
+
+        i = sched_setscheduler(0, policy, &param);
+        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)
 {
@@ -239,13 +348,10 @@ 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) {
@@ -254,8 +360,8 @@ int become_daemon(int dont_fork, const char *user)
         else debug(D_SYSTEM, "Successfully became user '%s'.", user);
     }
     else {
-        create_needed_dir(CACHE_DIR, getuid(), getgid());
-        create_needed_dir(VARLIB_DIR, getuid(), getgid());
+        create_needed_dir(netdata_configured_cache_dir, getuid(), getgid());
+        create_needed_dir(netdata_configured_varlib_dir, getuid(), getgid());
     }
 
     if(pidfd != -1)