[dpdk-dev] [PATCH v5 00/16] remove mbuf timestamp

Thomas Monjalon thomas at monjalon.net
Tue Nov 3 15:44:13 CET 2020


03/11/2020 15:17, Olivier Matz:
> On Tue, Nov 03, 2020 at 03:09:15PM +0100, Thomas Monjalon 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.
> > 
> > As a consequence, 8 bytes can be re-allocated to dynamic fields
> > in the first half of mbuf structure.
> > It is still open to change more the mbuf layout.
> > 
> > This mbuf layout change is important to allow adding more features
> > (consuming more dynamic fields) during the next year,
> > and can allow performance improvements with new usages in the first half.
[...]
> >  39 files changed, 440 insertions(+), 180 deletions(-)
> 
> For the series:
> Acked-by: Olivier Matz <olivier.matz at 6wind.com>

Applied, thanks for the help Olivier, David and Andrew.

Next step: decide whether we keep "free space" in the first half
for dynamic fields or move another field from the second half.




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