Re: [PATCH iwl-next] ixgbe: clean up adaptive interrupt moderation algorithm

Simon Horman
2026-04-03T13:31:55Z

On Fri, Mar 27, 2026 at 08:30:37AM +0100, Aleksandr Loktionov wrote:
> From: Alexander Duyck <alexander.h.duyck@intel.com>
>
> Improve the adaptive interrupt throttle (ITR) algorithm in several ways:
>
> - Lower IXGBE_ITR_ADAPTIVE_MAX_USECS from 126 to 84 us (12K interrupts/s
> minimum in bulk mode) to prevent RX starvation in full-blown bulk
> scenarios.
>
> - Add ixgbe_container_is_rx() helper to split the Rx vs Tx logic in
> ixgbe_update_itr(); Rx uses a latency-favouring path for small bursts
> (< 24 packets and < 12112 bytes), targeting 8x throughput growth per
> step.
>
> - Limit the ITR decrease in latency mode to at most 2 us per update so
> ACK workloads do not overdrive the moderation and starve TCP senders.
>
> - Add IXGBE_ITR_ADAPTIVE_MASK_USECS (= IXGBE_ITR_ADAPTIVE_LATENCY - 1
> = 0x7F) to mask out the mode flag bit 7 in ixgbe_set_itr(), replacing
> the open-coded ~IXGBE_ITR_ADAPTIVE_LATENCY.
>
> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
> Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

This patch is doing 4 things.
Please split it up.

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