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Diffstat (limited to 'doc/guides/prog_guide/metrics_lib.rst')
| -rw-r--r-- | doc/guides/prog_guide/metrics_lib.rst | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/doc/guides/prog_guide/metrics_lib.rst b/doc/guides/prog_guide/metrics_lib.rst index 5cbe17c9..e68e4e74 100644 --- a/doc/guides/prog_guide/metrics_lib.rst +++ b/doc/guides/prog_guide/metrics_lib.rst @@ -271,3 +271,12 @@ 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. |