Add option to change scheduler policy to SCHED_RR and increase scheduler priority

Set "realtime scheduling=yes" option to change Linux scheduler policy
to SCHED_RR and increase the priority to the maximum possible for the policy.

Change-Id: I3ecef5cbc3816cf2b56364bb4e806ae5ac093c23
Signed-off-by: Xavier Simonart <xavier.simonart@intel.com>

3 files changed, 28 insertions, 0 deletions

diff --git a/VNFs/DPPD-PROX/lconf.h b/VNFs/DPPD-PROX/lconf.h
index 4bfa705d..8ac1112e 100644
--- a/VNFs/DPPD-PROX/lconf.h
+++ b/VNFs/DPPD-PROX/lconf.h
@@ -52,6 +52,7 @@ struct lconf_msg {
 #define LCONF_FLAG_TX_DISTR_ACTIVE 0x00000004
 #define LCONF_FLAG_RX_BW_ACTIVE    0x00000008
 #define LCONF_FLAG_TX_BW_ACTIVE    0x00000010
+#define LCONF_FLAG_SCHED_RR    0x00000020
 
 struct lcore_cfg {
 	/* All tasks running at the moment. This is empty when the core is stopped. */
diff --git a/VNFs/DPPD-PROX/prox_args.c b/VNFs/DPPD-PROX/prox_args.c
index d77eab1a..45996db8 100644
--- a/VNFs/DPPD-PROX/prox_args.c
+++ b/VNFs/DPPD-PROX/prox_args.c
@@ -1262,6 +1262,9 @@ static int get_core_cfg(unsigned sindex, char *str, void *data)
 		return parse_int(&targ->byte_offset, pkey);
 	}
 
+	if (STR_EQ(str, "realtime scheduling")) {
+		return parse_flag(&lconf->flags, LCONF_FLAG_SCHED_RR, pkey);
+	}
 	if (STR_EQ(str, "name")) {
 		return parse_str(lconf->name, pkey, sizeof(lconf->name));
 	}
diff --git a/VNFs/DPPD-PROX/thread_generic.c b/VNFs/DPPD-PROX/thread_generic.c
index f596bf25..14fb943e 100644
--- a/VNFs/DPPD-PROX/thread_generic.c
+++ b/VNFs/DPPD-PROX/thread_generic.c
@@ -14,6 +14,7 @@
 // limitations under the License.
 */
 
+#include <pthread.h>
 #include <rte_cycles.h>
 #include <rte_table_hash.h>
 
@@ -83,6 +84,26 @@ static uint64_t tsc_ctrl(struct lcore_cfg *lconf)
 	return lconf->ctrl_timeout;
 }
 
+static void set_thread_policy(int policy)
+{
+	struct sched_param p;
+	int ret, old_policy, old_priority;
+
+	memset(&p, 0, sizeof(p));
+	ret = pthread_getschedparam(pthread_self(), &old_policy, &p);
+	if (ret) {
+		plog_err("Failed getting thread policy: %d\n", ret);
+		return;
+	}
+	old_priority = p.sched_priority;
+	p.sched_priority = sched_get_priority_max(policy);
+	ret = pthread_setschedparam(pthread_self(), policy, &p);
+	if (ret) {
+		plog_err("Failed setting thread priority: %d", ret);
+	} else
+		plog_info("Thread policy/priority changed from %d/%d to %d/%d\n", old_policy, old_priority, policy, p.sched_priority);
+}
+
 int thread_generic(struct lcore_cfg *lconf)
 {
 	struct task_base *tasks[MAX_TASKS_PER_CORE];
@@ -99,6 +120,9 @@ int thread_generic(struct lcore_cfg *lconf)
 	};
 	uint8_t n_tasks_run = lconf->n_tasks_run;
 
+	if (lconf->flags & LCONF_FLAG_SCHED_RR)
+		set_thread_policy(SCHED_RR);
+
 	if (lconf->period_func) {
 		tsc_tasks[2].tsc = cur_tsc + lconf->period_timeout;
 		tsc_tasks[2].tsc_task = tsc_period;