X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=doc%2Fguides%2Fprog_guide%2Fmetrics_lib.rst;h=eca855d60185f57a8468ad990788e65f9ce13c12;hb=e0ad8d2bdafcd74eb960bf96507fed11cc97d58c;hp=d52204fddd3531f66bb315f50f52d17bfe7a9aca;hpb=c17c27e8585deba739ce018b967544743a824c41;p=dpdk.git

diff --git a/doc/guides/prog_guide/metrics_lib.rst b/doc/guides/prog_guide/metrics_lib.rst
index d52204fddd..eca855d601 100644
--- a/doc/guides/prog_guide/metrics_lib.rst
+++ b/doc/guides/prog_guide/metrics_lib.rst
@@ -1,32 +1,5 @@
-..  BSD LICENSE
-    Copyright(c) 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.
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright(c) 2017 Intel Corporation.
 
 .. _Metrics_Library:
 
@@ -52,7 +25,7 @@ individual device. Since the metrics library is self-contained, the only
 restriction on port numbers is that they are less than ``RTE_MAX_ETHPORTS``
 - there is no requirement for the ports to actually exist.
 
-Initialising the library
+Initializing the library
 ------------------------
 
 Before the library can be used, it has to be initialized by calling
@@ -181,6 +154,20 @@ print out all metrics for a given port:
     }
 
 
+Deinitialising the library
+--------------------------
+
+Once the library usage is done, it must be deinitialized by calling
+``rte_metrics_deinit()`` which will free the shared memory reserved
+during initialization.
+
+.. code-block:: c
+
+    err = rte_metrics_deinit(void);
+
+If the return value is negative, it means deinitialization failed.
+This function **must** be called from a primary process.
+
 Bit-rate statistics library
 ---------------------------
 
@@ -298,3 +285,12 @@ de-initialise the latency library.
 .. code-block:: c
 
     rte_latencystats_uninit();
+
+Timestamp and latency calculation
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The Latency stats library marks the time in the timestamp field of the
+mbuf for the ingress packets and sets the ``PKT_RX_TIMESTAMP`` flag of
+``ol_flags`` for the mbuf to indicate the marked time as a valid one.
+At the egress, the mbufs with the flag set are considered having valid
+timestamp and are used for the latency calculation.