[PATCH] eal: add option --avail-cores to detect lcores

[Jianfeng Tan <jianfeng.tan@intel.com>]

This patch adds option, --avail-cores, to use lcores which are available
by calling pthread_getaffinity_np() to narrow down detected cores before
parsing coremask (-c), corelist (-l), and coremap (--lcores).

Test example:
$ taskset 0xc0000 ./examples/helloworld/build/helloworld \
		--avail-cores -m 1024

Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
---
 lib/librte_eal/common/eal_common_options.c | 52 ++++++++++++++++++++++++++++++
 lib/librte_eal/common/eal_options.h        |  2 ++
 2 files changed, 54 insertions(+)

diff --git a/lib/librte_eal/common/eal_common_options.c b/lib/librte_eal/common/eal_common_options.c
index 29942ea..dc4882d 100644
--- a/lib/librte_eal/common/eal_common_options.c
+++ b/lib/librte_eal/common/eal_common_options.c
@@ -95,6 +95,7 @@ eal_long_options[] = {
 	{OPT_VFIO_INTR,         1, NULL, OPT_VFIO_INTR_NUM        },
 	{OPT_VMWARE_TSC_MAP,    0, NULL, OPT_VMWARE_TSC_MAP_NUM   },
 	{OPT_XEN_DOM0,          0, NULL, OPT_XEN_DOM0_NUM         },
+	{OPT_AVAIL_CORES,       0, NULL, OPT_AVAIL_CORES_NUM      },
 	{0,                     0, NULL, 0                        }
 };
 
@@ -681,6 +682,37 @@ err:
 }
 
 static int
+eal_parse_avail_cores(void)
+{
+	int i, count;
+	pthread_t tid;
+	rte_cpuset_t cpuset;
+	struct rte_config *cfg = rte_eal_get_configuration();
+
+	tid = pthread_self();
+	if (pthread_getaffinity_np(tid, sizeof(rte_cpuset_t), &cpuset) != 0)
+		return -1;
+
+	for (i = 0, count = 0; i < RTE_MAX_LCORE; i++) {
+		if (lcore_config[i].detected && !CPU_ISSET(i, &cpuset)) {
+			RTE_LOG(DEBUG, EAL, "Flag lcore %u as undetected\n", i);
+			lcore_config[i].detected = 0;
+			lcore_config[i].core_index = -1;
+			cfg->lcore_role[i] = ROLE_OFF;
+			count++;
+		}
+	}
+	cfg->lcore_count -= count;
+	if (cfg->lcore_count == 0) {
+		RTE_LOG(ERR, EAL, "No lcores available\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+
+static int
 eal_parse_syslog(const char *facility, struct internal_config *conf)
 {
 	int i;
@@ -754,6 +786,10 @@ eal_parse_proc_type(const char *arg)
 	return RTE_PROC_INVALID;
 }
 
+static int param_coremask;
+static int param_corelist;
+static int param_coremap;
+
 int
 eal_parse_common_option(int opt, const char *optarg,
 			struct internal_config *conf)
@@ -775,6 +811,7 @@ eal_parse_common_option(int opt, const char *optarg,
 		break;
 	/* coremask */
 	case 'c':
+		param_coremask = 1;
 		if (eal_parse_coremask(optarg) < 0) {
 			RTE_LOG(ERR, EAL, "invalid coremask\n");
 			return -1;
@@ -782,6 +819,7 @@ eal_parse_common_option(int opt, const char *optarg,
 		break;
 	/* corelist */
 	case 'l':
+		param_corelist = 1;
 		if (eal_parse_corelist(optarg) < 0) {
 			RTE_LOG(ERR, EAL, "invalid core list\n");
 			return -1;
@@ -890,12 +928,25 @@ eal_parse_common_option(int opt, const char *optarg,
 		break;
 	}
 	case OPT_LCORES_NUM:
+		param_coremap = 1;
 		if (eal_parse_lcores(optarg) < 0) {
 			RTE_LOG(ERR, EAL, "invalid parameter for --"
 				OPT_LCORES "\n");
 			return -1;
 		}
 		break;
+	case OPT_AVAIL_CORES_NUM:
+		if (param_coremask || param_corelist || param_coremap) {
+			RTE_LOG(ERR, EAL, "should put --" OPT_AVAIL_CORES
+				" before -c, -l and --" OPT_LCORES "\n");
+			return -1;
+		}
+		if (eal_parse_avail_cores() < 0) {
+			RTE_LOG(ERR, EAL, "failed to use --"
+				OPT_AVAIL_CORES "\n");
+			return -1;
+		}
+		break;
 
 	/* don't know what to do, leave this to caller */
 	default:
@@ -990,6 +1041,7 @@ eal_common_usage(void)
 	       "                      ',' is used for single number separator.\n"
 	       "                      '( )' can be omitted for single element group,\n"
 	       "                      '@' can be omitted if cpus and lcores have the same value\n"
+	       "  --"OPT_AVAIL_CORES"       Use pthread_getaffinity_np() to detect cores to be used\n"
 	       "  --"OPT_MASTER_LCORE" ID   Core ID that is used as master\n"
 	       "  -n CHANNELS         Number of memory channels\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 a881c62..b2ddea3 100644
--- a/lib/librte_eal/common/eal_options.h
+++ b/lib/librte_eal/common/eal_options.h
@@ -83,6 +83,8 @@ enum {
 	OPT_VMWARE_TSC_MAP_NUM,
 #define OPT_XEN_DOM0          "xen-dom0"
 	OPT_XEN_DOM0_NUM,
+#define OPT_AVAIL_CORES       "avail-cores"
+	OPT_AVAIL_CORES_NUM,
 	OPT_LONG_MAX_NUM
 };
 
-- 
2.1.4