[dpdk-dev] [PATCH v2] 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>
---

changes in v2:
- rebase on HEAD including common options for BSD and Linux
- use strtol() instead of atoi() to check syntax errors
- unit tests

 app/test/test.c                             |  1 +
 app/test/test_eal_flags.c                   | 49 +++++++++++++++++++++++++++++
 lib/librte_eal/bsdapp/eal/eal.c             |  7 +++++
 lib/librte_eal/common/eal_common_options.c  | 31 ++++++++++++++++++
 lib/librte_eal/common/include/eal_options.h |  2 ++
 lib/librte_eal/linuxapp/eal/eal.c           |  7 +++++
 6 files changed, 97 insertions(+)

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 21e6cca..45020b8 100644
--- a/app/test/test_eal_flags.c
+++ b/app/test/test_eal_flags.c
@@ -520,6 +520,49 @@ 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"};
+	/* --master-lcore flag with invalid value */
+	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"};
+
+	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) {
+		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
@@ -1214,6 +1257,12 @@ 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/bsdapp/eal/eal.c b/lib/librte_eal/bsdapp/eal/eal.c
index ca99cb9..c764fec 100644
--- a/lib/librte_eal/bsdapp/eal/eal.c
+++ b/lib/librte_eal/bsdapp/eal/eal.c
@@ -354,6 +354,13 @@ eal_parse_args(int argc, char **argv)
 		if (opt == '?')
 			return -1;
 
+		if (opt == OPT_MASTER_LCORE_NUM && !coremask_ok) {
+			RTE_LOG(ERR, EAL, "please specify the master lcore id"
+				"after specifying the coremask\n");
+			eal_usage(prgname);
+			return -1;
+		}
+
 		ret = eal_parse_common_option(opt, optarg, &internal_config);
 		/* common parser is not happy */
 		if (ret < 0) {
diff --git a/lib/librte_eal/common/eal_common_options.c b/lib/librte_eal/common/eal_common_options.c
index 7a5d55e..9166ea1 100644
--- a/lib/librte_eal/common/eal_common_options.c
+++ b/lib/librte_eal/common/eal_common_options.c
@@ -64,6 +64,7 @@ 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},
@@ -163,6 +164,27 @@ 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)
+{
+	long master_lcore;
+	char *parsing_end;
+	struct rte_config *cfg = rte_eal_get_configuration();
+
+	errno = 0;
+	master_lcore = strtol(arg, &parsing_end, 0);
+	if (errno || parsing_end == arg)
+		return -1;
+
+	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, struct internal_config *conf)
 {
@@ -320,6 +342,14 @@ 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) {
@@ -364,6 +394,7 @@ eal_common_usage(void)
 	       "[--proc-type primary|secondary|auto]\n\n"
 	       "EAL common 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"
 	       "  -m MB        : memory to allocate (see also --"OPT_SOCKET_MEM")\n"
diff --git a/lib/librte_eal/common/include/eal_options.h b/lib/librte_eal/common/include/eal_options.h
index 22819ec..deb872d 100644
--- a/lib/librte_eal/common/include/eal_options.h
+++ b/lib/librte_eal/common/include/eal_options.h
@@ -43,6 +43,8 @@ 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"
diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
index 7a1d087..7fcb349 100644
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -550,6 +550,13 @@ eal_parse_args(int argc, char **argv)
 		if (opt == '?')
 			return -1;
 
+		if (opt == OPT_MASTER_LCORE_NUM && !coremask_ok) {
+			RTE_LOG(ERR, EAL, "please specify the master lcore id"
+				"after specifying the coremask\n");
+			eal_usage(prgname);
+			return -1;
+		}
+
 		ret = eal_parse_common_option(opt, optarg, &internal_config);
 		/* common parser is not happy */
 		if (ret < 0) {
-- 
2.1.3