New upstream version 17.11-rc3
[deb_dpdk.git] / lib / librte_ether / ethdev_profile.c
diff --git a/lib/librte_ether/ethdev_profile.c b/lib/librte_ether/ethdev_profile.c
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+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2017 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "ethdev_profile.h"
+
+/**
+ * This conditional block enables RX queues profiling by tracking wasted
+ * iterations, i.e. iterations which yielded no RX packets. Profiling is
+ * performed using the Instrumentation and Tracing Technology (ITT) API,
+ * employed by the Intel (R) VTune (TM) Amplifier.
+ */
+#ifdef RTE_ETHDEV_PROFILE_ITT_WASTED_RX_ITERATIONS
+
+#include <ittnotify.h>
+
+#define ITT_MAX_NAME_LEN (100)
+
+/**
+ * Auxiliary ITT structure belonging to Ethernet device and using to:
+ *   -  track RX queue state to determine whether it is wasting loop iterations
+ *   -  begin or end ITT task using task domain and task name (handle)
+ */
+struct itt_profile_rx_data {
+       /**
+        * ITT domains for each queue.
+        */
+       __itt_domain *domains[RTE_MAX_QUEUES_PER_PORT];
+       /**
+        * ITT task names for each queue.
+        */
+       __itt_string_handle *handles[RTE_MAX_QUEUES_PER_PORT];
+       /**
+        * Flags indicating the queues state. Possible values:
+        *   1 - queue is wasting iterations,
+        *   0 - otherwise.
+        */
+       uint8_t queue_state[RTE_MAX_QUEUES_PER_PORT];
+};
+
+/**
+ * The pool of *itt_profile_rx_data* structures.
+ */
+struct itt_profile_rx_data itt_rx_data[RTE_MAX_ETHPORTS];
+
+
+/**
+ * This callback function manages ITT tasks collection on given port and queue.
+ * It must be registered with rte_eth_add_rx_callback() to be called from
+ * rte_eth_rx_burst(). To find more comments see rte_rx_callback_fn function
+ * type declaration.
+ */
+static uint16_t
+collect_itt_rx_burst_cb(uint16_t port_id, uint16_t queue_id,
+       __rte_unused struct rte_mbuf *pkts[], uint16_t nb_pkts,
+       __rte_unused uint16_t max_pkts, __rte_unused void *user_param)
+{
+       if (unlikely(nb_pkts == 0)) {
+               if (!itt_rx_data[port_id].queue_state[queue_id]) {
+                       __itt_task_begin(
+                               itt_rx_data[port_id].domains[queue_id],
+                               __itt_null, __itt_null,
+                               itt_rx_data[port_id].handles[queue_id]);
+                       itt_rx_data[port_id].queue_state[queue_id] = 1;
+               }
+       } else {
+               if (unlikely(itt_rx_data[port_id].queue_state[queue_id])) {
+                       __itt_task_end(
+                               itt_rx_data[port_id].domains[queue_id]);
+                       itt_rx_data[port_id].queue_state[queue_id] = 0;
+               }
+       }
+       return nb_pkts;
+}
+
+/**
+ * Initialization of itt_profile_rx_data for a given Ethernet device.
+ * This function must be invoked when ethernet device is being configured.
+ * Result will be stored in the global array *itt_rx_data*.
+ *
+ * @param port_id
+ *  The port identifier of the Ethernet device.
+ * @param port_name
+ *  The name of the Ethernet device.
+ * @param rx_queue_num
+ *  The number of RX queues on specified port.
+ *
+ * @return
+ *  - On success, zero.
+ *  - On failure, a negative value.
+ */
+static inline int
+itt_profile_rx_init(uint16_t port_id, char *port_name, uint8_t rx_queue_num)
+{
+       uint16_t q_id;
+
+       for (q_id = 0; q_id < rx_queue_num; ++q_id) {
+               char domain_name[ITT_MAX_NAME_LEN];
+
+               snprintf(domain_name, sizeof(domain_name),
+                       "RXBurst.WastedIterations.Port_%s.Queue_%d",
+                       port_name, q_id);
+               itt_rx_data[port_id].domains[q_id]
+                       = __itt_domain_create(domain_name);
+
+               char task_name[ITT_MAX_NAME_LEN];
+
+               snprintf(task_name, sizeof(task_name),
+                       "port id: %d; queue id: %d",
+                       port_id, q_id);
+               itt_rx_data[port_id].handles[q_id]
+                       = __itt_string_handle_create(task_name);
+
+               itt_rx_data[port_id].queue_state[q_id] = 0;
+
+               if (!rte_eth_add_rx_callback(
+                       port_id, q_id, collect_itt_rx_burst_cb, NULL)) {
+                       return -rte_errno;
+               }
+       }
+
+       return 0;
+}
+#endif /* RTE_ETHDEV_PROFILE_ITT_WASTED_RX_ITERATIONS */
+
+int
+__rte_eth_profile_rx_init(__rte_unused uint16_t port_id,
+       __rte_unused struct rte_eth_dev *dev)
+{
+#ifdef RTE_ETHDEV_PROFILE_ITT_WASTED_RX_ITERATIONS
+       return itt_profile_rx_init(
+               port_id, dev->data->name, dev->data->nb_rx_queues);
+#endif
+       return 0;
+}