Re: [PATCH v3] latencystats: fix timestamp marking and latency calculation

[Thomas Monjalon <thomas@monjalon.net>]

25/09/2018 16:51, Reshma Pattan:
> Latency calculation logic is not correct for the case where
> packets gets dropped before TX. As for the dropped packets,
> the timestamp is not cleared, and such packets still gets
> counted for latency calculation in next runs, that will result
> in inaccurate latency measurement.
> 
> So fix this issue as below,
> 
> Before setting timestamp in mbuf, check mbuf don't have
> any prior valid time stamp flag set and after marking
> the timestamp, set mbuf flags to indicate timestamp is
> valid.
> 
> Before calculating timestamp check mbuf flags are set to
> indicate timestamp is valid.
> 
> With the above logic it is guaranteed that correct timestamps
> have been used.
> 
> Fixes: 5cd3cac9ed ("latency: added new library for latency stats")
> 
> CC: stable@dpdk.org
> 
> Reported-by: Bao-Long Tran <longtb5@viettel.com.vn>
> Signed-off-by: Reshma Pattan <reshma.pattan@intel.com>
> Tested-by: Bao-Long Tran <longtb5@viettel.com.vn>
> Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> 
> ---
> v3: style related fix
> v2: remove check for mbuf->timestamp
> ---

Applied, thanks