Backport: relayd: initialize the global fd tracker from fd_cap parameter

[lttng-tools.git] / src / bin / lttng-relayd / main.c

diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
index b44255779460289557b7f10640bf14da9f2a190a..72ecef2f2e49901c2392d0f658b50832b2e420d6 100644 (file)
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -34,11 +34,13 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <sys/resource.h>
 #include <inttypes.h>
 #include <urcu/futex.h>
 #include <urcu/uatomic.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <ctype.h>
 
 #include <lttng/lttng.h>
 #include <common/common.h>
@@ -148,6 +150,9 @@ static uint64_t last_relay_stream_id;
  */
 static struct relay_conn_queue relay_conn_queue;
 
+/* Cap of file desriptors to be in simultaneous use by the relay daemon. */
+static unsigned int lttng_opt_fd_cap;
+
 /* Global relay stream hash table. */
 struct lttng_ht *relay_streams_ht;
 
@@ -160,6 +165,9 @@ struct lttng_ht *sessions_ht;
 /* Relayd health monitoring */
 struct health_app *health_relayd;
 
+/* Global fd tracker. */
+struct fd_tracker *the_fd_tracker;
+
 static struct option long_options[] = {
        { "control-port", 1, 0, 'C', },
        { "data-port", 1, 0, 'D', },
@@ -167,6 +175,7 @@ static struct option long_options[] = {
        { "daemonize", 0, 0, 'd', },
        { "background", 0, 0, 'b', },
        { "group", 1, 0, 'g', },
+       { "fd-cap", 1, 0, '\0', },
        { "help", 0, 0, 'h', },
        { "output", 1, 0, 'o', },
        { "verbose", 0, 0, 'v', },
@@ -192,6 +201,9 @@ static void relayd_config_log(void)
        if (EXTRA_VERSION_DESCRIPTION[0] != '\0') {
                DBG("LTTng-relayd extra version description:\n\t" EXTRA_VERSION_DESCRIPTION "\n");
        }
+       if (EXTRA_VERSION_PATCHES[0] != '\0') {
+               DBG("LTTng-relayd extra patches:\n\t" EXTRA_VERSION_PATCHES "\n");
+       }
 }
 
 /*
@@ -206,9 +218,33 @@ static int set_option(int opt, const char *arg, const char *optname)
 
        switch (opt) {
        case 0:
-               fprintf(stderr, "option %s", optname);
-               if (arg) {
-                       fprintf(stderr, " with arg %s\n", arg);
+               if (!strcmp(optname, "fd-cap")) {
+                       unsigned long v;
+
+                       errno = 0;
+                       v = strtoul(arg, NULL, 0);
+                       if (errno != 0 || !isdigit(arg[0])) {
+                               ERR("Wrong value in --fd-cap parameter: %s", arg);
+                               ret = -1;
+                               goto end;
+                       }
+                       if (v < DEFAULT_RELAYD_MINIMAL_FD_CAP) {
+                               ERR("File descriptor cap must be set to at least %d",
+                                               DEFAULT_RELAYD_MINIMAL_FD_CAP);
+                       }
+                       if (v >= UINT_MAX) {
+                               ERR("File descriptor cap overflow in --fd-cap parameter: %s", arg);
+                               ret = -1;
+                               goto end;
+                       }
+                       lttng_opt_fd_cap = (unsigned int) v;
+                       DBG3("File descriptor cap set to %u", lttng_opt_fd_cap);
+
+               } else {
+                       fprintf(stderr, "unknown option %s", optname);
+                       if (arg) {
+                               fprintf(stderr, " with arg %s\n", arg);
+                       }
                }
                break;
        case 'C':
@@ -534,6 +570,18 @@ static int set_options(int argc, char **argv)
                        goto exit;
                }
        }
+       if (lttng_opt_fd_cap == 0) {
+               int ret;
+               struct rlimit rlimit;
+
+               ret = getrlimit(RLIMIT_NOFILE, &rlimit);
+               if (ret) {
+                       PERROR("Failed to get file descriptor limit");
+                       retval = -1;
+               }
+
+               lttng_opt_fd_cap = rlimit.rlim_cur;
+       }
 
        if (!opt_group_output_by_session && !opt_group_output_by_host) {
                /* Group by host by default */
@@ -547,13 +595,9 @@ exit:
 
 static void print_global_objects(void)
 {
-       rcu_register_thread();
-
        print_viewer_streams();
        print_relay_streams();
        print_sessions();
-
-       rcu_unregister_thread();
 }
 
 /*
@@ -585,6 +629,7 @@ static void relayd_cleanup(void)
        if (tracing_group_name_override) {
                free((void *) tracing_group_name);
        }
+       fd_tracker_log(the_fd_tracker);
 }
 
 /*
@@ -3269,7 +3314,6 @@ int main(int argc, char **argv)
                }
        }
 
-
        if (opt_working_directory) {
                ret = utils_change_working_dir(opt_working_directory);
                if (ret) {
@@ -3277,6 +3321,19 @@ int main(int argc, char **argv)
                        goto exit_options;
                }
        }
+       /*
+        * The RCU thread registration (and use, through the fd-tracker's
+        * creation) is done after the daemonization to allow us to not
+        * deal with liburcu's fork() management as the call RCU needs to
+        * be restored.
+        */
+       rcu_register_thread();
+
+       the_fd_tracker = fd_tracker_create(lttng_opt_fd_cap);
+       if (!the_fd_tracker) {
+               retval = -1;
+               goto exit_options;
+       }
 
        /* Initialize thread health monitoring */
        health_relayd = health_app_create(NR_HEALTH_RELAYD_TYPES);
@@ -3440,6 +3497,9 @@ exit_options:
        /* Ensure all prior call_rcu are done. */
        rcu_barrier();
 
+       fd_tracker_destroy(the_fd_tracker);
+       rcu_unregister_thread();
+
        if (!retval) {
                exit(EXIT_SUCCESS);
        } else {