diff mbox series

[net-next,3/4] i40e, xsk: increase budget for AF_XDP path

Message ID 20200702153730.575738-4-bjorn.topel@gmail.com
State Superseded
Delegated to: Anthony Nguyen
Headers show
Series i40e driver performance tweaks for AF_XDP | expand

Commit Message

Björn Töpel July 2, 2020, 3:37 p.m. UTC 
From: Björn Töpel <bjorn.topel@intel.com>

The napi_budget, meaning the number of received packets that are
allowed to be processed for each napi invocation, takes into
consideration that each received packet is aimed for the kernel
networking stack.

That is not the case for the AF_XDP receive path, where the cost of
each packet is significantly less. Therefore, this commit disregards
the napi budget and increases it to 256. Processing 256 packets
targeted for AF_XDP is still less work than 64 (napi budget) packets
going to the kernel networking stack.

The performance for the rx_drop scenario is up 7%.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_xsk.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Bowers, AndrewX July 8, 2020, 8:44 p.m. UTC | #1 
> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of
> Björn Töpel
> Sent: Thursday, July 2, 2020 8:37 AM
> To: intel-wired-lan@lists.osuosl.org
> Cc: netdev@vger.kernel.org; bpf@vger.kernel.org; Topel, Bjorn
> <bjorn.topel@intel.com>; Karlsson, Magnus <magnus.karlsson@intel.com>
> Subject: [Intel-wired-lan] [PATCH net-next 3/4] i40e, xsk: increase budget for
> AF_XDP path
> 
> From: Björn Töpel <bjorn.topel@intel.com>
> 
> The napi_budget, meaning the number of received packets that are allowed
> to be processed for each napi invocation, takes into consideration that each
> received packet is aimed for the kernel networking stack.
> 
> That is not the case for the AF_XDP receive path, where the cost of each
> packet is significantly less. Therefore, this commit disregards the napi budget
> and increases it to 256. Processing 256 packets targeted for AF_XDP is still less
> work than 64 (napi budget) packets going to the kernel networking stack.
> 
> The performance for the rx_drop scenario is up 7%.
> 
> Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
> ---
>  drivers/net/ethernet/intel/i40e/i40e_xsk.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)

Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 1f2dd591dbf1..99f4afdc403d 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -265,6 +265,8 @@  static void i40e_inc_ntc(struct i40e_ring *rx_ring)
 	rx_ring->next_to_clean = ntc;
 }
 
+#define I40E_XSK_CLEAN_RX_BUDGET 256U
+
 /**
  * i40e_clean_rx_irq_zc - Consumes Rx packets from the hardware ring
  * @rx_ring: Rx ring
@@ -280,7 +282,7 @@  int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
 	bool failure = false;
 	struct sk_buff *skb;
 
-	while (likely(total_rx_packets < (unsigned int)budget)) {
+	while (likely(total_rx_packets < I40E_XSK_CLEAN_RX_BUDGET)) {
 		union i40e_rx_desc *rx_desc;
 		struct xdp_buff **bi;
 		unsigned int size;