[PATCH v2] service: add API for service count per lcore

[Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>]

This new API returns the number of services that are running on a specific
service core. It allows an application to decide which service core to run
a new service on.

Signed-off-by: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>
---

v2 changes:
  - reword the commit title according to the check-git-log.sh
  - modify return types
  - add function to .map file

 lib/librte_eal/bsdapp/eal/rte_eal_version.map   |  7 +++++++
 lib/librte_eal/common/include/rte_service.h     | 13 +++++++++++++
 lib/librte_eal/common/rte_service.c             | 13 +++++++++++++
 lib/librte_eal/linuxapp/eal/rte_eal_version.map |  7 +++++++
 4 files changed, 40 insertions(+)

diff --git a/lib/librte_eal/bsdapp/eal/rte_eal_version.map b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
index aac6fd7..5fe8d79 100644
--- a/lib/librte_eal/bsdapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
@@ -237,3 +237,10 @@ EXPERIMENTAL {
 	rte_service_unregister;

 } DPDK_17.08;
+
+EXPERIMENTAL {
+	global:
+
+	rte_service_lcore_count_services;
+
+} DPDK_17.11;
diff --git a/lib/librte_eal/common/include/rte_service.h b/lib/librte_eal/common/include/rte_service.h
index 7c6f738..9537ae5 100644
--- a/lib/librte_eal/common/include/rte_service.h
+++ b/lib/librte_eal/common/include/rte_service.h
@@ -374,6 +374,19 @@ int32_t rte_service_lcore_list(uint32_t array[], uint32_t n);
  * @warning
  * @b EXPERIMENTAL: this API may change without prior notice
  *
+ * Get the numer of services running on the supplied lcore.
+ *
+ * @param Lcore Id of the service core.
+ * @retval >=0 Number of services registered to this core.
+ * @retval -EINVAL Invalid lcore provided
+ * @retval -ENOTSUP The provided lcore is not a service core.
+ */
+int32_t rte_service_lcore_count_services(uint32_t lcore);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
  * Dumps any information available about the service. If service is NULL,
  * dumps info for all services.
  */
diff --git a/lib/librte_eal/common/rte_service.c b/lib/librte_eal/common/rte_service.c
index 7efb76d..616bad3 100644
--- a/lib/librte_eal/common/rte_service.c
+++ b/lib/librte_eal/common/rte_service.c
@@ -397,6 +397,19 @@ rte_service_lcore_list(uint32_t array[], uint32_t n)
 }

 int32_t
+rte_service_lcore_count_services(uint32_t lcore)
+{
+	if (lcore >= RTE_MAX_LCORE)
+		return -EINVAL;
+
+	struct core_state *cs = &lcore_states[lcore];
+	if (!cs->is_service_core)
+		return -ENOTSUP;
+
+	return __builtin_popcountll(cs->service_mask);
+}
+
+int32_t
 rte_service_start_with_defaults(void)
 {
 	/* create a default mapping from cores to services, then start the
diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
index 3a8f154..e848c45 100644
--- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
@@ -242,3 +242,10 @@ EXPERIMENTAL {
 	rte_service_unregister;

 } DPDK_17.08;
+
+EXPERIMENTAL {
+	global:
+
+	rte_service_lcore_count_services;
+
+} DPDK_17.11;
--
2.7.4