[PATCH bpf-next 0/6] ice: post-mbuf fixes

From: Alexander Lobakin
Date: Fri Feb 10 2023 - 12:11:10 EST


The set grew from the poor performance of %BPF_F_TEST_XDP_LIVE_FRAMES
when the ice-backed device is a sender. Initially there were around
3.3 Mpps / thread, while I have 5.5 on skb-based pktgen...

After fixing 0005 (0004 is a prereq for it) first (strange thing nobody
noticed that earlier), I started catching random OOMs. This is how 0002
(and partially 0001) appeared.
0003 is a suggestion from Maciej to not waste time on refactoring dead
lines. 0006 is a "cherry on top" to get away with the final 6.7 Mpps.
4.5 of 6 are fixes, but only the first three are tagged, since it then
starts being tricky. I may backport them manually later on.

TL;DR for the series is that shortcuts are good, but only as long as
they don't make the driver miss important things. %XDP_TX is purely
driver-local, however .ndo_xdp_xmit() is not, and sometimes assumptions
can be unsafe there.

With that series and also one core code patch[0], "live frames" and
xdp-trafficgen are now safe'n'fast on ice (probably more to come).

[0] https://lore.kernel.org/all/20230209172827.874728-1-alexandr.lobakin@xxxxxxxxx
---
Goes to directly to bpf-next as touches the recently added/changed code.

Alexander Lobakin (6):
ice: fix ice_tx_ring::xdp_tx_active underflow
ice: fix XDP Tx ring overrun
ice: remove two impossible branches on XDP Tx cleaning
ice: robustify cleaning/completing XDP Tx buffers
ice: fix freeing XDP frames backed by Page Pool
ice: micro-optimize .ndo_xdp_xmit() path

drivers/net/ethernet/intel/ice/ice_txrx.c | 67 +++++++++-----
drivers/net/ethernet/intel/ice/ice_txrx.h | 37 ++++++--
drivers/net/ethernet/intel/ice/ice_txrx_lib.c | 88 ++++++++++++-------
drivers/net/ethernet/intel/ice/ice_txrx_lib.h | 4 +-
drivers/net/ethernet/intel/ice/ice_xsk.c | 12 +--
5 files changed, 136 insertions(+), 72 deletions(-)

--
2.39.1