[dpdk-dev] [PATCH] eal/linuxapp: Add parameter to specify master lcore id

[Simon Kuenzer <simon.kuenzer@neclab.eu>]

This commit enables users to specify the lcore id that
is used as master lcore.

Signed-off-by: Simon Kuenzer <simon.kuenzer@neclab.eu>
---
 lib/librte_eal/linuxapp/eal/eal.c |   33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
index 573fd06..4ad5b9b 100644
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -101,6 +101,7 @@
 #define OPT_XEN_DOM0    "xen-dom0"
 #define OPT_CREATE_UIO_DEV "create-uio-dev"
 #define OPT_VFIO_INTR    "vfio-intr"
+#define OPT_MASTER_LCORE "master-lcore"
 
 #define RTE_EAL_BLACKLIST_SIZE	0x100
 
@@ -336,6 +337,7 @@ eal_usage(const char *prgname)
 	       "[--proc-type primary|secondary|auto] \n\n"
 	       "EAL options:\n"
 	       "  -c COREMASK  : A hexadecimal bitmask of cores to run on\n"
+	       "  --"OPT_MASTER_LCORE" ID: Core ID that is used as master\n"
 	       "  -n NUM       : Number of memory channels\n"
 		   "  -v           : Display version information on startup\n"
 	       "  -d LIB.so    : add driver (can be used multiple times)\n"
@@ -468,6 +470,21 @@ eal_parse_coremask(const char *coremask)
 	return 0;
 }
 
+/* Changes the lcore id of the master thread */
+static int
+eal_parse_master_lcore(const char *arg)
+{
+	struct rte_config *cfg = rte_eal_get_configuration();
+	int master_lcore = atoi(arg);
+
+	if (!(master_lcore >= 0 && master_lcore < RTE_MAX_LCORE))
+		return -1;
+	if (cfg->lcore_role[master_lcore] != ROLE_RTE)
+		return -1;
+	cfg->master_lcore = master_lcore;
+	return 0;
+}
+
 static int
 eal_parse_syslog(const char *facility)
 {
@@ -653,6 +670,7 @@ eal_parse_args(int argc, char **argv)
 		{OPT_HUGE_DIR, 1, 0, 0},
 		{OPT_NO_SHCONF, 0, 0, 0},
 		{OPT_PROC_TYPE, 1, 0, 0},
+		{OPT_MASTER_LCORE, 1, 0, 0},
 		{OPT_FILE_PREFIX, 1, 0, 0},
 		{OPT_SOCKET_MEM, 1, 0, 0},
 		{OPT_PCI_WHITELIST, 1, 0, 0},
@@ -802,6 +820,21 @@ eal_parse_args(int argc, char **argv)
 			else if (!strcmp(lgopts[option_index].name, OPT_PROC_TYPE)) {
 				internal_config.process_type = eal_parse_proc_type(optarg);
 			}
+			else if (!strcmp(lgopts[option_index].name, OPT_MASTER_LCORE)) {
+				if (!coremask_ok) {
+					RTE_LOG(ERR, EAL, "please specify the master "
+							"lcore id after specifying "
+							"the coremask\n");
+					eal_usage(prgname);
+					return -1;
+				}
+				if (eal_parse_master_lcore(optarg) < 0) {
+					RTE_LOG(ERR, EAL, "invalid parameter for --"
+							OPT_MASTER_LCORE "\n");
+					eal_usage(prgname);
+					return -1;
+				}
+			}
 			else if (!strcmp(lgopts[option_index].name, OPT_FILE_PREFIX)) {
 				internal_config.hugefile_prefix = optarg;
 			}
-- 
1.7.10.4