udevd: autotune max_childs/max_childs_running

diff --git a/udevcontrol.c b/udevcontrol.c
index 3044d02f0b6a02e832277798c63305677e0a9427..9231f2e08474d50a3f9cb78bf48caaaa0b39e6a5 100644 (file)
--- a/udevcontrol.c
+++ b/udevcontrol.c
@@ -53,12 +53,13 @@ void log_message (int priority, const char *format, ...)
 static void usage(void)
 {
        printf("Usage: udevcontrol COMMAND\n"
-               "  log_priority=<level> set the udev log level for the daemon\n"
-               "  stop_exec_queue      keep udevd from executing events, queue only\n"
-               "  start_exec_queue     execute events, flush queue\n"
-               "  reload_rules         reloads the rules files\n"
-               "  max_childs=<N>       maximum number of childs running at the same time\n"
-               "  --help               print this help text\n\n");
+               "  log_priority=<level>   set the udev log level for the daemon\n"
+               "  stop_exec_queue        keep udevd from executing events, queue only\n"
+               "  start_exec_queue       execute events, flush queue\n"
+               "  reload_rules           reloads the rules files\n"
+               "  max_childs=<N>         maximum number of childs\n"
+               "  max_childs_running=<N> maximum number of childs running at the same time\n"
+               "  --help                 print this help text\n\n");
 }
 
 int main(int argc, char *argv[], char *envp[])
@@ -104,11 +105,33 @@ int main(int argc, char *argv[], char *envp[])
                        *intval = log_priority(val);
                        info("send log_priority=%i", *intval);
                } else if (!strncmp(arg, "max_childs=", strlen("max_childs="))) {
+                       char *endp;
+                       int count;
+
                        intval = (int *) ctrl_msg.buf;
                        val = &arg[strlen("max_childs=")];
                        ctrl_msg.type = UDEVD_CTRL_SET_MAX_CHILDS;
-                       *intval = atoi(val);
+                       count = strtoul(val, &endp, 0);
+                       if (endp[0] != '\0' || count < 1) {
+                               fprintf(stderr, "invalid number\n");
+                               goto exit;
+                       }
+                       *intval = count;
                        info("send max_childs=%i", *intval);
+               } else if (!strncmp(arg, "max_childs_running=", strlen("max_childs_running="))) {
+                       char *endp;
+                       int count;
+
+                       intval = (int *) ctrl_msg.buf;
+                       val = &arg[strlen("max_childs_running=")];
+                       ctrl_msg.type = UDEVD_CTRL_SET_MAX_CHILDS_RUNNING;
+                       count = strtoul(val, &endp, 0);
+                       if (endp[0] != '\0' || count < 1) {
+                               fprintf(stderr, "invalid number\n");
+                               goto exit;
+                       }
+                       *intval = count;
+                       info("send max_childs_running=%i", *intval);
                } else if (strcmp(arg, "help") == 0  || strcmp(arg, "--help") == 0  || strcmp(arg, "-h") == 0) {
                        usage();
                        goto exit;

diff --git a/udevd.c b/udevd.c
index 45e9aae7717ff23ff6ead8ae54db5318f0ee16ed..af9e118c55061146b4952f416b8fb9385c534386 100644 (file)
--- a/udevd.c
+++ b/udevd.c
@@ -310,7 +310,68 @@ static void msg_queue_insert(struct udevd_uevent_msg *msg)
        run_exec_q = 1;
 }
 
-/* runs event and removes event from run queue when finished */
+static int mem_size_mb(void)
+{
+       int f;
+       char buf[8192];
+       long int len;
+       const char *pos;
+       long int memsize;
+
+       f = open("/proc/meminfo", O_RDONLY);
+       if (f == -1)
+               return -1;
+
+       len = read(f, buf, sizeof(buf)-1);
+       close(f);
+
+       if (len <= 0)
+               return -1;
+       buf[len] = '\0';
+
+       pos = strstr(buf, "MemTotal: ");
+       if (pos == NULL)
+               return -1;
+
+       if (sscanf(pos, "MemTotal: %ld kB", &memsize) != 1)
+               return -1;
+
+       return memsize / 1024;
+}
+
+static int cpu_count(void)
+{
+       int f;
+       char buf[32768];
+       int len;
+       const char *pos;
+       int count = 0;
+
+       f = open("/proc/stat", O_RDONLY);
+       if (f == -1)
+               return -1;
+
+       len = read(f, buf, sizeof(buf)-1);
+       close(f);
+       if (len <= 0)
+               return -1;
+       buf[len] = '\0';
+
+       pos = strstr(buf, "cpu");
+       if (pos == NULL)
+               return -1;
+
+       while (pos != NULL) {
+               if (strncmp(pos, "cpu", 3) == 0 &&isdigit(pos[3]))
+                       count++;
+               pos = strstr(&pos[3], "cpu");
+       }
+
+       if (count == 0)
+               return -1;
+       return count;
+}
+
 static int running_processes(void)
 {
        int f;
@@ -325,11 +386,9 @@ static int running_processes(void)
 
        len = read(f, buf, sizeof(buf)-1);
        close(f);
-
        if (len <= 0)
                return -1;
-       else
-               buf[len] = '\0';
+       buf[len] = '\0';
 
        pos = strstr(buf, "procs_running ");
        if (pos == NULL)
@@ -625,12 +684,17 @@ static void get_ctrl_msg(void)
                info("udevd message (UDEVD_SET_MAX_CHILDS) received, max_childs=%i", *intval);
                max_childs = *intval;
                break;
+       case UDEVD_CTRL_SET_MAX_CHILDS_RUNNING:
+               intval = (int *) ctrl_msg.buf;
+               info("udevd message (UDEVD_SET_MAX_CHILDS_RUNNING) received, max_childs=%i", *intval);
+               max_childs_running = *intval;
+               break;
        case UDEVD_CTRL_RELOAD_RULES:
                info("udevd message (RELOAD_RULES) received");
                reload_config = 1;
                break;
        default:
-               dbg("unknown message type");
+               err("unknown control message type");
        }
 }
 
@@ -998,16 +1062,26 @@ int main(int argc, char *argv[], char *envp[])
        value = getenv("UDEVD_MAX_CHILDS");
        if (value)
                max_childs = strtoul(value, NULL, 10);
-       else
-               max_childs = UDEVD_MAX_CHILDS;
+       else {
+               int memsize = mem_size_mb();
+               if (memsize > 0)
+                       max_childs = 128 + (memsize / 4);
+               else
+                       max_childs = UDEVD_MAX_CHILDS;
+       }
        info("initialize max_childs to %u", max_childs);
 
        /* start to throttle forking if maximum number of _running_ childs is reached */
        value = getenv("UDEVD_MAX_CHILDS_RUNNING");
        if (value)
                max_childs_running = strtoull(value, NULL, 10);
-       else
-               max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
+       else {
+               int cpus = cpu_count();
+               if (cpus > 0)
+                       max_childs_running = 8 + (8 * cpus);
+               else
+                       max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
+       }
        info("initialize max_childs_running to %u", max_childs_running);
 
        /* clear environment for forked event processes */

diff --git a/udevd.h b/udevd.h
index b852b5224d40f000851cd2654b06e6dd5764954a..688e6d52ef19d817ba384dd340c4339e57bd3151 100644 (file)
--- a/udevd.h
+++ b/udevd.h
@@ -46,6 +46,7 @@ enum udevd_ctrl_msg_type {
        UDEVD_CTRL_START_EXEC_QUEUE,
        UDEVD_CTRL_SET_LOG_LEVEL,
        UDEVD_CTRL_SET_MAX_CHILDS,
+       UDEVD_CTRL_SET_MAX_CHILDS_RUNNING,
        UDEVD_CTRL_RELOAD_RULES,
 };