[dpdk-dev] [PATCH 10/10] eal: add option --master-lcore

[Thomas Monjalon <thomas.monjalon@6wind.com>]

From: Simon Kuenzer <simon.kuenzer@neclab.eu>

Enable users to specify the lcore id that is used as master lcore.

Signed-off-by: Simon Kuenzer <simon.kuenzer@neclab.eu>
Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
---
 app/test/test.c                            |  1 +
 app/test/test_eal_flags.c                  | 51 ++++++++++++++++++++++++++++++
 lib/librte_eal/common/eal_common_options.c | 39 ++++++++++++++++++++---
 lib/librte_eal/common/eal_options.h        |  2 ++
 4 files changed, 89 insertions(+), 4 deletions(-)

diff --git a/app/test/test.c b/app/test/test.c
index 9bee6bb..2fecff5 100644
--- a/app/test/test.c
+++ b/app/test/test.c
@@ -82,6 +82,7 @@ do_recursive_call(void)
 	} actions[] =  {
 			{ "run_secondary_instances", test_mp_secondary },
 			{ "test_missing_c_flag", no_action },
+			{ "test_master_lcore_flag", no_action },
 			{ "test_missing_n_flag", no_action },
 			{ "test_no_hpet_flag", no_action },
 			{ "test_whitelist_flag", no_action },
diff --git a/app/test/test_eal_flags.c b/app/test/test_eal_flags.c
index 5ad89c5..6a6ef08 100644
--- a/app/test/test_eal_flags.c
+++ b/app/test/test_eal_flags.c
@@ -549,6 +549,51 @@ test_missing_c_flag(void)
 }
 
 /*
+ * Test --master-lcore option with matching coremask
+ */
+static int
+test_master_lcore_flag(void)
+{
+#ifdef RTE_EXEC_ENV_BSDAPP
+	/* BSD target doesn't support prefixes at this point */
+	const char *prefix = "";
+#else
+	char prefix[PATH_MAX], tmp[PATH_MAX];
+	if (get_current_prefix(tmp, sizeof(tmp)) == NULL) {
+		printf("Error - unable to get current prefix!\n");
+		return -1;
+	}
+	snprintf(prefix, sizeof(prefix), "--file-prefix=%s", tmp);
+#endif
+
+	/* --master-lcore flag but no value */
+	const char *argv1[] = { prgname, prefix, mp_flag, "-n", "1", "-c", "3", "--master-lcore"};
+	/* --master-lcore flag with invalid value */
+	const char *argv2[] = { prgname, prefix, mp_flag, "-n", "1", "-c", "3", "--master-lcore", "-1"};
+	const char *argv3[] = { prgname, prefix, mp_flag, "-n", "1", "-c", "3", "--master-lcore", "X"};
+	/* master lcore not in coremask */
+	const char *argv4[] = { prgname, prefix, mp_flag, "-n", "1", "-c", "3", "--master-lcore", "2"};
+	/* valid value */
+	const char *argv5[] = { prgname, prefix, mp_flag, "-n", "1", "-c", "3", "--master-lcore", "1"};
+	/* valid value set before coremask */
+	const char *argv6[] = { prgname, prefix, mp_flag, "-n", "1", "--master-lcore", "1", "-c", "3"};
+
+	if (launch_proc(argv1) == 0
+			|| launch_proc(argv2) == 0
+			|| launch_proc(argv3) == 0
+			|| launch_proc(argv4) == 0) {
+		printf("Error - process ran without error with wrong --master-lcore\n");
+		return -1;
+	}
+	if (launch_proc(argv5) != 0
+			|| launch_proc(argv6) != 0) {
+		printf("Error - process did not run ok with valid --master-lcore\n");
+		return -1;
+	}
+	return 0;
+}
+
+/*
  * Test that the app doesn't run without the -n flag. In all cases
  * should give an error and fail to run.
  * Since -n is not compulsory for MP, we instead use --no-huge and --no-shconf
@@ -1237,6 +1282,12 @@ test_eal_flags(void)
 		return ret;
 	}
 
+	ret = test_master_lcore_flag();
+	if (ret < 0) {
+		printf("Error in test_master_lcore_flag()\n");
+		return ret;
+	}
+
 	ret = test_missing_n_flag();
 	if (ret < 0) {
 		printf("Error in test_missing_n_flag()\n");
diff --git a/lib/librte_eal/common/eal_common_options.c b/lib/librte_eal/common/eal_common_options.c
index c9df8f5..54bd31d 100644
--- a/lib/librte_eal/common/eal_common_options.c
+++ b/lib/librte_eal/common/eal_common_options.c
@@ -67,6 +67,7 @@ eal_short_options[] =
 const struct option
 eal_long_options[] = {
 	{OPT_HUGE_DIR, 1, 0, OPT_HUGE_DIR_NUM},
+	{OPT_MASTER_LCORE, 1, 0, OPT_MASTER_LCORE_NUM},
 	{OPT_PROC_TYPE, 1, 0, OPT_PROC_TYPE_NUM},
 	{OPT_NO_SHCONF, 0, 0, OPT_NO_SHCONF_NUM},
 	{OPT_NO_HPET, 0, 0, OPT_NO_HPET_NUM},
@@ -186,8 +187,6 @@ eal_parse_coremask(const char *coremask)
 				}
 				cfg->lcore_role[idx] = ROLE_RTE;
 				lcore_config[idx].core_index = count;
-				if (count == 0)
-					cfg->master_lcore = idx;
 				count++;
 			} else {
 				cfg->lcore_role[idx] = ROLE_OFF;
@@ -257,8 +256,6 @@ eal_parse_corelist(const char *corelist)
 			for (idx = min; idx <= max; idx++) {
 				cfg->lcore_role[idx] = ROLE_RTE;
 				lcore_config[idx].core_index = count;
-				if (count == 0)
-					cfg->master_lcore = idx;
 				count++;
 			}
 			min = RTE_MAX_LCORE;
@@ -274,6 +271,22 @@ eal_parse_corelist(const char *corelist)
 	return 0;
 }
 
+/* Changes the lcore id of the master thread */
+static int
+eal_parse_master_lcore(const char *arg)
+{
+	char *parsing_end;
+	struct rte_config *cfg = rte_eal_get_configuration();
+
+	errno = 0;
+	cfg->master_lcore = (uint32_t) strtol(arg, &parsing_end, 0);
+	if (errno || parsing_end[0] != 0)
+		return -1;
+	if (cfg->master_lcore >= RTE_MAX_LCORE)
+		return -1;
+	return 0;
+}
+
 static int
 eal_parse_syslog(const char *facility, struct internal_config *conf)
 {
@@ -439,6 +452,14 @@ eal_parse_common_option(int opt, const char *optarg,
 		conf->process_type = eal_parse_proc_type(optarg);
 		break;
 
+	case OPT_MASTER_LCORE_NUM:
+		if (eal_parse_master_lcore(optarg) < 0) {
+			RTE_LOG(ERR, EAL, "invalid parameter for --"
+					OPT_MASTER_LCORE "\n");
+			return -1;
+		}
+		break;
+
 	case OPT_VDEV_NUM:
 		if (rte_eal_devargs_add(RTE_DEVTYPE_VIRTUAL,
 				optarg) < 0) {
@@ -480,10 +501,15 @@ int
 eal_adjust_config(struct internal_config *internal_cfg)
 {
 	int i;
+	struct rte_config *cfg = rte_eal_get_configuration();
 
 	if (internal_config.process_type == RTE_PROC_AUTO)
 		internal_config.process_type = eal_proc_type_detect();
 
+	/* default master lcore is the first one */
+	if (cfg->master_lcore == 0)
+		cfg->master_lcore = rte_get_next_lcore(-1, 0, 0);
+
 	/* if no memory amounts were requested, this will result in 0 and
 	 * will be overridden later, right after eal_hugepage_info_init() */
 	for (i = 0; i < RTE_MAX_NUMA_NODES; i++)
@@ -502,6 +528,10 @@ eal_check_common_options(struct internal_config *internal_cfg)
 			"-c or -l\n");
 		return -1;
 	}
+	if (cfg->lcore_role[cfg->master_lcore] != ROLE_RTE) {
+		RTE_LOG(ERR, EAL, "Master lcore is not enabled for DPDK\n");
+		return -1;
+	}
 
 	if (internal_cfg->process_type == RTE_PROC_INVALID) {
 		RTE_LOG(ERR, EAL, "Invalid process type specified\n");
@@ -550,6 +580,7 @@ eal_common_usage(void)
 	       "  -l CORELIST  : List of cores to run on\n"
 	       "                 The argument format is <c1>[-c2][,c3[-c4],...]\n"
 	       "                 where c1, c2, etc are core indexes between 0 and %d\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"
 	       "  -m MB        : memory to allocate (see also --"OPT_SOCKET_MEM")\n"
diff --git a/lib/librte_eal/common/eal_options.h b/lib/librte_eal/common/eal_options.h
index f58965c..e476f8d 100644
--- a/lib/librte_eal/common/eal_options.h
+++ b/lib/librte_eal/common/eal_options.h
@@ -45,6 +45,8 @@ enum {
 	OPT_LONG_MIN_NUM = 256,
 #define OPT_HUGE_DIR    "huge-dir"
 	OPT_HUGE_DIR_NUM = OPT_LONG_MIN_NUM,
+#define OPT_MASTER_LCORE "master-lcore"
+	OPT_MASTER_LCORE_NUM,
 #define OPT_PROC_TYPE   "proc-type"
 	OPT_PROC_TYPE_NUM,
 #define OPT_NO_SHCONF   "no-shconf"
-- 
2.1.3