> From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf Of Maciej > Fijalkowski > Sent: Thursday, August 19, 2021 5:30 PM > To: intel-wired-lan@xxxxxxxxxxxxxxxx > Cc: joamaki@xxxxxxxxx; Lobakin, Alexandr <alexandr.lobakin@xxxxxxxxx>; > netdev@xxxxxxxxxxxxxxx; toke@xxxxxxxxxx; bjorn@xxxxxxxxxx; kuba@xxxxxxxxxx; > bpf@xxxxxxxxxxxxxxx; davem@xxxxxxxxxxxxx; Karlsson, Magnus > <magnus.karlsson@xxxxxxxxx> > Subject: [Intel-wired-lan] [PATCH v7 intel-next 6/9] ice: propagate xdp_ring onto > rx_ring > > With rings being split, it is now convenient to introduce a pointer to XDP ring within > the Rx ring. For XDP_TX workloads this means that xdp_rings array access will be > skipped, which was executed per each processed frame. > > Also, read the XDP prog once per NAPI and if prog is present, set up the local > xdp_ring pointer. Reading prog a single time was discussed in [1] with some > concern raised by Toke around dispatcher handling and having the need for going > through the RCU grace period in the ndo_bpf driver callback, but ice currently is > torning down NAPI instances regardless of the prog presence on VSI. > > Although the pointer to XDP ring introduced to Rx ring makes things a lot > slimmer/simpler, I still feel that single prog read per NAPI lifetime is beneficial. > > Further patch that will introduce the fallback path will also get a profit from that as > xdp_ring pointer will be set during the XDP rings setup. > > [1]: https://lore.kernel.org/bpf/87k0oseo6e.fsf@xxxxxxx/ > > Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx> > --- > drivers/net/ethernet/intel/ice/ice_main.c | 3 +++ > drivers/net/ethernet/intel/ice/ice_txrx.c | 23 +++++++++-------- > drivers/net/ethernet/intel/ice/ice_txrx.h | 1 + > drivers/net/ethernet/intel/ice/ice_txrx_lib.c | 10 +++----- > drivers/net/ethernet/intel/ice/ice_txrx_lib.h | 2 +- > drivers/net/ethernet/intel/ice/ice_xsk.c | 25 +++++++++++-------- > 6 files changed, 35 insertions(+), 29 deletions(-) > Tested-by: George Kuruvinakunnel <george.kuruvinakunnel@xxxxxxxxx>
