Re: [RFC PATCH net-next v2 0/6] net: xilinx: axienet: Enable adaptive IRQ coalescing with DIM

From: Nelson, Shannon
Date: Mon Sep 09 2024 - 21:34:28 EST


On 9/9/2024 4:52 PM, Sean Anderson wrote:

To improve performance without sacrificing latency under low load,
enable DIM. While I appreciate not having to write the library myself, I
do think there are many unusual aspects to DIM, as detailed in the last
patch.

This series depends on [1-2] and is therefore marked RFC. This series is
otherwise ready to merge.

[1] https://lore.kernel.org/netdev/20240909230908.1319982-1-sean.anderson@xxxxxxxxx/
[2] https://lore.kernel.org/netdev/20240909231904.1322387-1-sean.anderson@xxxxxxxxx/

Changes in v2:
- Add some symbolic constants for IRQ delay timer
- Report an error for bad coalesce settings
- Don't use spin_lock_irqsave when we know the context
- Split the CR calculation refactor from runtime coalesce settings
adjustment support for easier review.
- Have axienet_update_coalesce_rx/tx take the cr value/mask instead of
calculating it with axienet_calc_cr. This will make it easier to add
partial updates in the next few commits.
- Get coalesce parameters from driver state
- Don't take the RTNL in axienet_rx_dim_work to avoid deadlock. Instead,
calculate a partial cr update that axienet_update_coalesce_rx can
perform under a spin lock.
- Use READ/WRITE_ONCE when accessing/modifying rx_irqs

Sean Anderson (6):
net: xilinx: axienet: Add some symbolic constants for IRQ delay timer
net: xilinx: axienet: Report an error for bad coalesce settings
net: xilinx: axienet: Combine CR calculation
net: xilinx: axienet: Support adjusting coalesce settings while
running
net: xilinx: axienet: Get coalesce parameters from driver state
net: xilinx: axienet: Enable adaptive IRQ coalescing with DIM

drivers/net/ethernet/xilinx/Kconfig | 1 +
drivers/net/ethernet/xilinx/xilinx_axienet.h | 31 +-
.../net/ethernet/xilinx/xilinx_axienet_main.c | 320 ++++++++++++++----
3 files changed, 273 insertions(+), 79 deletions(-)

--
2.35.1.1320.gc452695387.dirty



Except for a couple of comment nits pointed out in 3/6 and 6/6, this set seems reasonable.

Reviewed by: Shannon Nelson <shannon.nelson@xxxxxxx>