netdata now adjusts its scheduling priority to IDLE and its Out-Of-Memory score to...

diff --git a/src/daemon.c b/src/daemon.c
index 9d4d5b32b4c3822f93dd4c846ba9cfc1d059d39d..925abbf302a2bd082b3712408c1fd6371d08ec0a 100644 (file)
--- a/src/daemon.c
+++ b/src/daemon.c
@@ -1,4 +1,5 @@
 #include "common.h"
+#include <sched.h>
 
 char pidfile[FILENAME_MAX + 1] = "";
 
@@ -102,6 +103,36 @@ int become_user(const char *username, int access_fd, int output_fd, int error_fd
        return(0);
 }
 
+void oom_score_adj(int score) {
+       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;
+               close(fd);
+       }
+
+       if(!done)
+               error("Cannot adjust my Out-Of-Memory score to %d.", score);
+       else
+               info("Adjusted my Out-Of-Memory score to %d.", score);
+}
+
+int sched_setscheduler_idle(void) {
+       const struct sched_param param = {
+               .sched_priority = 0
+       };
+
+       int i = sched_setscheduler(0, SCHED_IDLE, &param);
+       if(i != 0)
+               error("Cannot adjust my scheduling priority to IDLE.");
+       else
+               info("Adjusted my scheduling priority to IDLE.");
+
+       return i;
+}
+
 int become_daemon(int dont_fork, int close_all_files, const char *user, const char *input, const char *output, const char *error, const char *access, int *access_fd, FILE **access_fp)
 {
        fflush(NULL);
@@ -192,11 +223,9 @@ int become_daemon(int dont_fork, int close_all_files, const char *user, const ch
                        perror("Cannot become session leader.");
                        exit(2);
                }
-       }
 
-       // fork() again
-       if(!dont_fork) {
-               int i = fork();
+               // fork() again
+               i = fork();
                if(i == -1) {
                        perror("cannot fork");
                        exit(1);
@@ -206,9 +235,6 @@ int become_daemon(int dont_fork, int close_all_files, const char *user, const ch
                }
        }
 
-       // Set new file permissions
-       umask(0);
-
        // close all files
        if(close_all_files) {
                int i;
@@ -286,6 +312,18 @@ int become_daemon(int dont_fork, int close_all_files, const char *user, const ch
                else error("Failed to open pidfile '%s'.", pidfile);
        }
 
+       // Set new file permissions
+       umask(0002);
+
+       // adjust my Out-Of-Memory score
+       oom_score_adj(1000);
+
+       // never become a problem
+       if(sched_setscheduler_idle() != 0) {
+               if(nice(19) == -1) error("Cannot lower my CPU priority.");
+               else info("Set my nice value to 19.");
+       }
+
        if(user && *user) {
                if(become_user(user, (access_fd)?*access_fd:-1, output_fd, error_fd, pidfd) != 0) {
                        error("Cannot become user '%s'. Continuing as we are.", user);

diff --git a/src/main.c b/src/main.c
index f93fef7b300a1e065bf03bcea78f3b211209b54e..2065b506a845a7e3cea999860f66fd321f54e52a 100644 (file)
--- a/src/main.c
+++ b/src/main.c
@@ -621,9 +621,6 @@ int main(int argc, char **argv)
                create_listen_sockets();
        }
 
-       // never become a problem
-       if(nice(20) == -1) error("Cannot lower my CPU priority.");
-
        if(become_daemon(dont_fork, 0, user, input_log_file, output_log_file, error_log_file, access_log_file, &access_fd, &stdaccess) == -1)
                fatal("Cannot demonize myself.");