From: Magnus Karlsson <magnus.karlsson@intel.com> To: magnus.karlsson@intel.com, bjorn.topel@intel.com, intel-wired-lan@lists.osuosl.org, jeffrey.t.kirsher@intel.com Cc: maciej.fijalkowski@intel.com, maciejromanfijalkowski@gmail.com, netdev@vger.kernel.org Subject: [PATCH net-next 2/2] i40e: eliminate division in napi_poll data path Date: Mon, 22 Jun 2020 15:21:23 +0200 [thread overview] Message-ID: <1592832083-23249-3-git-send-email-magnus.karlsson@intel.com> (raw) In-Reply-To: <1592832083-23249-1-git-send-email-magnus.karlsson@intel.com> 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(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 0ce9d1e..da73a7d 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 ? -- 2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: Magnus Karlsson <magnus.karlsson@intel.com> To: intel-wired-lan@osuosl.org Subject: [Intel-wired-lan] [PATCH net-next 2/2] i40e: eliminate division in napi_poll data path Date: Mon, 22 Jun 2020 15:21:23 +0200 [thread overview] Message-ID: <1592832083-23249-3-git-send-email-magnus.karlsson@intel.com> (raw) In-Reply-To: <1592832083-23249-1-git-send-email-magnus.karlsson@intel.com> 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(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 0ce9d1e..da73a7d 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 ? -- 2.7.4
next prev parent reply other threads:[~2020-06-22 13:21 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-06-22 13:21 [PATCH net-next 0/2] i40e: improve AF_XDP performance Magnus Karlsson 2020-06-22 13:21 ` [Intel-wired-lan] " Magnus Karlsson 2020-06-22 13:21 ` [PATCH net-next 1/2] i40e: optimize AF_XDP Tx completion path Magnus Karlsson 2020-06-22 13:21 ` [Intel-wired-lan] " Magnus Karlsson 2020-06-23 1:00 ` Samudrala, Sridhar 2020-06-23 1:00 ` Samudrala, Sridhar 2020-06-23 5:02 ` Magnus Karlsson 2020-06-23 5:02 ` Magnus Karlsson 2020-06-22 13:21 ` Magnus Karlsson [this message] 2020-06-22 13:21 ` [Intel-wired-lan] [PATCH net-next 2/2] i40e: eliminate division in napi_poll data path Magnus Karlsson
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