On Wed, Jan 14, 2026 at 04:31:31PM +0100, Morten Brørup wrote: > > > If I'm not mistaken, the mbuf library is not a barrier for fast- > > freeing > > > segmented packet mbufs, and thus fast-free of jumbo frames is > > possible. > > > > > > We need a driver developer to confirm that my suggested approach - > > > resetting the mbuf fields, incl. 'm->nb_segs' and 'm->next', when > > > preparing the Tx descriptor - is viable. > > > > > Excellent analysis, Morten. If I get a chance some time this release > > cycle, > > I will try implementing this change in our drivers, see if any > > difference > > is made. > > Bruce, > > Have you had a chance to look into the driver change requirements? > If not, could you please try scratching the surface, to build a gut feeling. > Prototype implementation done and posted as a patch to this thread[1]. (It applies on top of my "combine multiple Intel scalar Tx paths" patchset[2]).
The logic is not terribly complicated, and running a quick perf test with scattered Tx enabled (to force use of scalar path, this optimization doesn't apply to vector path*) shows a small perf increase from it using testpmd iofwd. /Bruce [1] https://patches.dpdk.org/project/dpdk/patch/[email protected]/ [2] https://patches.dpdk.org/project/dpdk/list/?series=37033 * Vector path already has support for fast-free, and disallows use of scattered packets, so there is nothing to optimize for here.
