> -----Original Message----- > From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf Of Maciej > Fijalkowski > Sent: Thursday, August 11, 2022 11:52 PM > To: intel-wired-lan@xxxxxxxxxxxxxxxx > Cc: alasdair.mcwilliam@xxxxxxxxxxx; xdp-newbies@xxxxxxxxxxxxxxx; Karlsson, > Magnus <magnus.karlsson@xxxxxxxxx> > Subject: [Intel-wired-lan] [PATCH intel-net 2/2] ice: xsk: use Rx ring's XDP ring > when picking NAPI context > > Ice driver allocates per cpu XDP queues so that redirect path can safely use > smp_processor_id() as an index to the array. At the same time though, XDP rings > are used to pick NAPI context to call napi_schedule() or set > NAPIF_STATE_MISSED. When user reduces queue count, say to 8, and > num_possible_cpus() of underlying platform is 44, then this means queue vectors > with correlated NAPI contexts will carry several XDP queues. > > This in turn can result in a broken behavior where NAPI context of interest will > never be scheduled and AF_XDP socket will not process any traffic. > > To fix this, let us change the way how XDP rings are assigned to Rx rings and > use this information later on when setting ice_tx_ring::xsk_pool pointer. For each > Rx ring, grab the associated queue vector and walk through Tx ring's linked list. > Once we stumble upon XDP ring in it, assign this ring to ice_rx_ring::xdp_ring. > > Previous [0] approach of fixing this issue was for txonly scenario because of the > described grouping of XDP rings across queue vectors. So, relying on Rx ring > meant that NAPI context could be scheduled with a queue vector without XDP ring > with associated XSK pool. > > [0]: https://lore.kernel.org/netdev/20220707161128.54215-1- > maciej.fijalkowski@xxxxxxxxx/ > > Fixes: 2d4238f55697 ("ice: Add support for AF_XDP") > Fixes: 22bf877e528f ("ice: introduce XDP_TX fallback path") > Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx> > --- > drivers/net/ethernet/intel/ice/ice.h | 36 +++++++++++++++-------- > drivers/net/ethernet/intel/ice/ice_lib.c | 4 +-- > drivers/net/ethernet/intel/ice/ice_main.c | 25 +++++++++++----- > drivers/net/ethernet/intel/ice/ice_xsk.c | 12 ++++---- > 4 files changed, 48 insertions(+), 29 deletions(-) > Tested-by: George Kuruvinakunnel <george.kuruvinakunnel@xxxxxxxxx>
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