Message ID | 1592905458-850-3-git-send-email-magnus.karlsson@intel.com |
---|---|
State | Awaiting Upstream |
Delegated to: | David Miller |
Headers | show |
Series | i40e: improve AF_XDP performance | expand |
> -----Original Message----- > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of > Magnus Karlsson > Sent: Tuesday, June 23, 2020 2:44 AM > To: Karlsson, Magnus <magnus.karlsson@intel.com>; Topel, Bjorn > <bjorn.topel@intel.com>; intel-wired-lan@lists.osuosl.org; Kirsher, Jeffrey T > <jeffrey.t.kirsher@intel.com>; Samudrala, Sridhar > <sridhar.samudrala@intel.com> > Cc: maciejromanfijalkowski@gmail.com; Fijalkowski, Maciej > <maciej.fijalkowski@intel.com>; netdev@vger.kernel.org > Subject: [Intel-wired-lan] [PATCH net-next v2 2/3] i40e: eliminate division in > napi_poll data path > > Eliminate a division in the napi_poll data path. This division is executed even > though it is only needed in the rare case when there are not enough > interrupt lines so they have to be shared between queue pairs. Instead, just > test for this case and only execute the division if needed. The code has been > lifted from the ice driver. > > Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> > --- > drivers/net/ethernet/intel/i40e/i40e_txrx.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 9334abd..60fa102 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -2595,10 +2595,16 @@ int i40e_napi_poll(struct napi_struct *napi, int budget) if (budget <= 0) goto tx_only; - /* We attempt to distribute budget to each Rx queue fairly, but don't - * allow the budget to go below 1 because that would exit polling early. - */ - budget_per_ring = max(budget/q_vector->num_ringpairs, 1); + /* normally we have 1 Rx ring per q_vector */ + if (unlikely(q_vector->num_ringpairs > 1)) + /* We attempt to distribute budget to each Rx queue fairly, but + * don't allow the budget to go below 1 because that would exit + * polling early. + */ + budget_per_ring = max_t(int, budget / q_vector->num_ringpairs, 1); + else + /* Max of 1 Rx ring in this q_vector so give it the budget */ + budget_per_ring = budget; i40e_for_each_ring(ring, q_vector->rx) { int cleaned = ring->xsk_umem ?
Eliminate a division in the napi_poll data path. This division is executed even though it is only needed in the rare case when there are not enough interrupt lines so they have to be shared between queue pairs. Instead, just test for this case and only execute the division if needed. The code has been lifted from the ice driver. Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com> --- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)