speed improvements: change scheduler to SCHED_FIFO, Disable realtime throttling, use in-memory db for sqlite core channels table (set core-db-name to 'core' in switch.conf.xml for previous behaviour of using the core sqlite file, now only aliases will be in the persistant db)

src/include/switch_core.h

@@ -2303,6 +2303,9 @@ SWITCH_DECLARE(switch_status_t) _switch_core_db_handle(switch_cache_db_handle_t
 SWITCH_DECLARE(switch_status_t) _switch_core_recovery_db_handle(switch_cache_db_handle_t ** dbh, const char *file, const char *func, int line);
 #define switch_core_recovery_db_handle(_a) _switch_core_recovery_db_handle(_a, __FILE__, __SWITCH_FUNC__, __LINE__)
 
+SWITCH_DECLARE(switch_status_t) _switch_core_persist_db_handle(switch_cache_db_handle_t ** dbh, const char *file, const char *func, int line);
+#define switch_core_persist_db_handle(_a) _switch_core_persist_db_handle(_a, __FILE__, __SWITCH_FUNC__, __LINE__)
+
 SWITCH_DECLARE(switch_bool_t) switch_cache_db_test_reactive(switch_cache_db_handle_t *db,
 															const char *test_sql, const char *drop_sql, const char *reactive_sql);
 SWITCH_DECLARE(switch_status_t) switch_cache_db_persistant_execute(switch_cache_db_handle_t *dbh, const char *sql, uint32_t retries);

src/switch_core.c

@@ -731,16 +731,36 @@ SWITCH_DECLARE(int32_t) set_realtime_priority(void)
 	 * Try to use a round-robin scheduler
 	 * with a fallback if that does not work
 	 */
+	int fd;
+	const char *rt = "/proc/sys/kernel/sched_rt_runtime_us";
+	char data[] = "-1\n";
 	struct sched_param sched = { 0 };
 	sched.sched_priority = 1;
-	if (sched_setscheduler(0, SCHED_RR, &sched)) {
+	if (sched_setscheduler(0, SCHED_FIFO, &sched)) {
 		sched.sched_priority = 0;
 		if (sched_setscheduler(0, SCHED_OTHER, &sched)) {
 			return -1;
 		}
 	}
+
+	if ((fd = open(rt, O_WRONLY)) > 0) {
+		int r;
+		
+		if (!(r = write(fd, data, sizeof(data)))) {
+			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Error Disablling RT limits [%s][%d]\n", rt, r);
+		} else {
+			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Disabling RT throttling.\n");
+		}
+		close(fd);
+	} else {
+		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Error opening %s\n", rt);
+	}
+
+	
 #endif
 
+	
+
 #ifdef HAVE_SETPRIORITY
 	/*
 	 * setpriority() works on FreeBSD (6.2), nice() doesn't

src/switch_core_sqldb.c

@@ -176,7 +176,7 @@ static switch_cache_db_handle_t *get_handle(const char *db_str, const char *user
 }
 
 
-#define SWITCH_CORE_DB "core"
+#define SWITCH_CORE_DB "file:scoreboard?mode=memory&cache=shared"
 /*!
   \brief Open the default system database
 */
@@ -218,6 +218,49 @@ SWITCH_DECLARE(switch_status_t) _switch_core_db_handle(switch_cache_db_handle_t
 	return r;
 }
 
+#define SWITCH_CORE_PERSIST_DB "core"
+/*!
+  \brief Open the default system database
+*/
+SWITCH_DECLARE(switch_status_t) _switch_core_persist_db_handle(switch_cache_db_handle_t **dbh, const char *file, const char *func, int line)
+{
+	switch_cache_db_connection_options_t options = { {0} };
+	switch_status_t r;
+	
+	if (!sql_manager.manage) {
+		return SWITCH_STATUS_FALSE;
+	}
+
+	if (zstr(runtime.odbc_dsn)) {
+		if (switch_test_flag((&runtime), SCF_CORE_ODBC_REQ)) {
+			return SWITCH_STATUS_FALSE;
+		}
+
+		if (runtime.dbname) {
+			options.core_db_options.db_path = runtime.dbname;
+		} else {
+			options.core_db_options.db_path = SWITCH_CORE_PERSIST_DB;
+		}
+		r = _switch_cache_db_get_db_handle(dbh, SCDB_TYPE_CORE_DB, &options, file, func, line);
+		
+	} else {
+		options.odbc_options.dsn = runtime.odbc_dsn;
+		options.odbc_options.user = runtime.odbc_user;
+		options.odbc_options.pass = runtime.odbc_pass;
+
+		r = _switch_cache_db_get_db_handle(dbh, SCDB_TYPE_ODBC, &options, file, func, line);
+	}
+
+	/* I *think* we can do without this now, if not let me know 
+	   if (r == SWITCH_STATUS_SUCCESS && !(*dbh)->io_mutex) {
+	   (*dbh)->io_mutex = sql_manager.io_mutex;
+	   }
+	*/
+
+	return r;
+}
+
+
 #define SWITCH_CORE_RECOVERY_DB "core_recovery"
 SWITCH_DECLARE(switch_status_t) _switch_core_recovery_db_handle(switch_cache_db_handle_t **dbh, const char *file, const char *func, int line)
 {