On Tue, 03 Nov 2020 17:20:20 +0100 Thomas Monjalon <tho...@monjalon.net> wrote:
> 03/11/2020 17:08, Stephen Hemminger: > > On Tue, 3 Nov 2020 15:09:15 +0100 > > Thomas Monjalon <tho...@monjalon.net> wrote: > > > > > The mbuf field timestamp was announced to be removed for three reasons: > > > - a dynamic field already exist, used for Tx only > > > - this field always used 8 bytes even if unneeded > > > - this field is in the first half (cacheline) of mbuf > > > > > > After this series, the dynamic field timestamp is used for both Rx and Tx > > > with separate dynamic flags to distinguish when the value is meaningful > > > without resetting the field during forwarding. > > > > There should be a place in documentation which describes all the > > dynamic fields and their meaning. For example, which drivers/features > > set the field and the exact meaning. > > A dynamic field can be registered by anyone, including the apps. > So you will never get a full list. > The meaning of each field should be defined in its context > (driver, lib or app). > > > Is the timestamp in HW units, UTC units, or TSC ticks? > > The timestamp unit is driver-specific. > It is explained in ethdev API: > http://doc.dpdk.org/api/rte__ethdev_8h.html#a4346bf07a0d302c9ba4fe06baffd3196 Are there are any conventions we should use in this area? There could be overlapping usage between subsystems?
