Add description about Tx scheduling timstamp upper limit. It timstamp exceed the value it is marked by PMD as being into "too-distant-future" and not scheduled at all (is being sent without any wait).
Signed-off-by: Viacheslav Ovsiienko <viachesl...@mellanox.com> --- v1->v2: typo fix doc/guides/nics/mlx5.rst | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst index 90202c0..b9bd3db 100644 --- a/doc/guides/nics/mlx5.rst +++ b/doc/guides/nics/mlx5.rst @@ -253,6 +253,13 @@ Limitations reported via device xstats to assist applications to detect the time-related problems. + The timestamp upper "too-distant-future" limit at the moment of invoking + the tx_burst routine can be estimated as ``tx_pp`` devarog (in nanoseconds) + multiplied by 2^23. Please note, for the testpmd txonly testcase the limit + is deduced from the expression:: + + (n_tx_descriptors / burst_size + 1) * inter_burst_gap + There is no any packet reordering according timestamps is supposed, neither within packet burst, nor between packets, it is an entirely application responsibility to generate packets and its timestamps -- 1.8.3.1
