MT#55283 support custom uring buffer size

Change-Id: I020df2427f690d84130ca218c0b24cc8136fc07d

docs/rtpengine.md

@@ -1187,6 +1187,12 @@ call to inject-DTMF won't be sent to __\-\-dtmf-log-dest=__ or __\-\-listen-tcp-
     not actual CPU usage but rather indicates time spent waiting for a network
     event, and so should be considered the same as idle CPU time._
 
+- __\-\-io-uring-buffers=__*INT*
+
+    Number of `io_uring` entries in the buffer allocated from the kernel per
+    thread. Defaults to 16384. Must be large enough so that submission entries
+    and completion entries are always available when needed.
+
 - __\-\-dtls-cert-cipher=prime256v1__\|__RSA__
 
     Choose the type of key to use for the signature used by the self-signed

lib/auxlib.c

@@ -201,6 +201,7 @@ void config_load(int *argc, char ***argv, GOptionEntry *app_entries, const char
 		{ "poller-size",	0,0,	G_OPTION_ARG_INT,	&rtpe_common_config_ptr->poller_size,	"Max poller items per iteration",	"INT"		},
 #ifdef HAVE_LIBURING
 		{ "io-uring",		0,0,	G_OPTION_ARG_NONE,	&rtpe_common_config_ptr->io_uring,	"Use io_uring",				NULL },
+		{ "io-uring-buffers",	0,0,	G_OPTION_ARG_INT,	&rtpe_common_config_ptr->io_uring_buffers,"Number of io_uring entries per thread","INT" },
 #endif
 		{ "evs-lib-path",	0,0,	G_OPTION_ARG_FILENAME,	&rtpe_common_config_ptr->evs_lib_path,	"Location of .so for 3GPP EVS codec",	"FILE"		},
 #ifdef HAVE_CODEC_CHAIN
@@ -403,6 +404,13 @@ out:
 		rtpe_common_config_ptr->codec_chain_async = 0;
 #endif
 
+#if HAVE_LIBURING
+	if (rtpe_common_config_ptr->io_uring_buffers == 0)
+		rtpe_common_config_ptr->io_uring_buffers = 16384;
+	else if (rtpe_common_config_ptr->io_uring_buffers < 0)
+		die("Invalid value for --io-uring-buffers");
+#endif
+
 	return;
 
 err:

lib/auxlib.h

@@ -35,6 +35,7 @@ struct rtpengine_common_config {
 	int thread_stack;
 	int poller_size;
 	gboolean io_uring;
+	int io_uring_buffers;
 	int max_log_line_length;
 	char *evs_lib_path;
 	char *codec_chain_lib_path;

lib/uring.c

@@ -99,7 +99,7 @@ static unsigned int __uring_thread_loop(void) {
 
 void uring_thread_init(void) {
 	struct io_uring_params params = {0};
-	int ret = io_uring_queue_init_params(4096, &rtpe_uring, &params);
+	int ret = io_uring_queue_init_params(rtpe_common_config_ptr->io_uring_buffers, &rtpe_uring, &params);
 	if (ret)
 		die("io_uring init failed (%s)", strerror(errno));