Re: [PATCH iwl-next 2/4] ixgbe: add ixgbe_container_is_rx() helper and refine RX adaptive ITR

[Simon Horman <horms@kernel.org>]

On Tue, Sep 15, 2026 at 02:55:36PM +0200, Aleksandr Loktionov wrote:
> From: Alexander Duyck <alexander.h.duyck@intel.com>
> 
> Add an ixgbe_container_is_rx() helper to cleanly distinguish RX from TX
> ring containers inside ixgbe_update_itr().
> 
> Refine the RX-specific latency-detection path:
> 
>  - Replace the shared "packets < 4 or bytes < 9000" threshold with an
>    RX-specific check of "1..23 packets and bytes < 12112".  When that
>    condition holds, target 8x the observed byte count in the next
>    interval by computing avg_wire_size = (bytes + packets * 24) * 2,
>    clamped to [2560, 12800], and jumping directly to the speed-based
>    ITR calculation.  This provides finer-grained control over low-rate
>    RX latency workloads without affecting TX.
> 
>  - Remove the separate "no packets" special-case block.  When packets
>    is 0 it falls into the "< 48" branch.  The mode-tracking logic in
>    that branch is extended: fewer than 8 packets forces latency mode;
>    8..47 packets preserves the current mode.  This replaces the old
>    unconditional "add LATENCY flag from ring_container->itr" carried
>    over from the removed block.
> 
>  - Remove the adjust_by_size label and the associated "halve
>    avg_wire_size in latency mode" step.  The Rx latency path now
>    pre-calculates avg_wire_size independently and the bulk path no
>    longer needs the halving to compensate for incorrect thresholds.
>    Rename the jump target to adjust_for_speed to reflect its purpose.
> 
> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
> Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

Reviewed-by: Simon Horman <horms@kernel.org>