RE: [Intel-wired-lan] [PATCH net-next v2 1/3] i40e, xsk: remove HW descriptor prefetch in AF_XDP path

From: Intel-wired-lan <redacted> On Behalf Of
Björn Töpel
Sent: Tuesday, August 25, 2020 4:36 AM
To: intel-wired-lan@lists.osuosl.org
Cc: netdev@vger.kernel.org; bpf@vger.kernel.org; Topel, Bjorn
[off-list ref]; Karlsson, Magnus [off-list ref];
kuba@kernel.org
Subject: [Intel-wired-lan] [PATCH net-next v2 1/3] i40e, xsk: remove HW
descriptor prefetch in AF_XDP path

From: Björn Töpel <redacted>

The software prefetching of HW descriptors has a negative impact on
the performance. Therefore, it is now removed.

Performance for the rx_drop benchmark increased with 2%.

Signed-off-by: Björn Töpel <redacted>
---
 drivers/net/ethernet/intel/i40e/i40e_txrx.c        | 13 +++++++++++++
 drivers/net/ethernet/intel/i40e/i40e_txrx_common.h | 13 -------------
 drivers/net/ethernet/intel/i40e/i40e_xsk.c         | 12 ++++++++++++
 3 files changed, 25 insertions(+), 13 deletions(-)

Tested-by: Aaron Brown <redacted>