On Wed, Sep 21, 2016 at 11:45 AM, Jakub Kicinski <kubak...@wp.pl> wrote: > On Wed, 21 Sep 2016 10:39:40 -0700, Tom Herbert wrote: >> On Wed, Sep 21, 2016 at 10:26 AM, Jakub Kicinski <kubak...@wp.pl> wrote: >> > On Tue, 20 Sep 2016 17:01:39 -0700, Alexei Starovoitov wrote: >> >> > - Reduces the amount of code and complexity needed in drivers to >> >> > manage XDP >> >> >> >> hmm: >> >> 534 insertions(+), 144 deletions(-) >> >> looks like increase in complexity instead. >> > >> > and more to come to tie this with HW offloads. >> >> The amount of driver code did decrease with these patches: >> >> drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 64 >> ++++---------------------- >> drivers/net/ethernet/mellanox/mlx4/en_rx.c | 25 ++++------ >> drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 1 - >> >> Minimizing complexity being added to drivers for XDP is critical since >> we basically asking every driver to replicate the function. This >> property also should also apply to HW offloads, the more complexity we >> can abstract out drivers into a common backend infrastructure the >> better for supporting across different drivers. > > I'm in the middle of writing/testing XDP support for the Netronome's > driver and generic infra is very much appreciated ;) In my experience > the 50 lines of code which are required for assigning the programs and > freeing them aren't really a big deal, though. >
50 lines in one driver is not a big deal, 50 lines in a hundred drivers is! I learned this lesson in BQL which was well abstracted out to be minimally invasive but we still saw many issues because of the pecularities of different drivers. > Let's also separate putting xdp_prog in netdevice/napi_struct from the > generic hook infra. All the simplifications to the driver AFAICS come > from the former. If everyone is fine with growing napi_struct we can do > that but IMHO this is not an argument for the generic infra :)
