[PATCH iwl-next v4 0/3] i40e: add runtime-tunable ATR sample rate

[mheib@redhat.com]

From: Mohammad Heib <mheib@redhat.com>

This series makes the Flow Director ATR sample rate configurable at
runtime through a devlink parameter.

On systems with many queues and high-rate TCP workloads, the fixed
default sampling interval can cause frequent Flow Director
reprogramming and TCP packet reordering. The optimal interval depends
on the workload and system configuration.

Patch 1 moves atr_sample_rate from per-ring to PF level, since it is
a global policy.

Patch 2 exposes it as a devlink runtime parameter so administrators
can tune it without rebuilding the driver.

Patch 3 fixes a pre-existing issue where re-enabling ATR via ethtool
private flags did not trigger a ring reset, leaving fd_ena stale in
the TX queue HW context.

Changes since v3:
 - Added READ_ONCE() in i40e_atr() for lockless access to
   pf->atr_sample_rate (patch 1).
 - Added WRITE_ONCE()/READ_ONCE() in devlink setter/getter (patch 2)
 - New patch: trigger PF reset when re-enabling ATR (patch 3)

---
Mohammad Heib (3):
  i40e: move ATR sample rate from ring to PF level
  i40e: add devlink parameter for Flow Director ATR sample rate
  i40e: trigger PF reset when re-enabling ATR via ethtool

 Documentation/networking/devlink/i40e.rst     | 20 +++++++++++
 drivers/net/ethernet/intel/i40e/i40e.h        |  1 +
 .../net/ethernet/intel/i40e/i40e_devlink.c    | 36 +++++++++++++++++++
 .../net/ethernet/intel/i40e/i40e_ethtool.c    |  7 ++++
 drivers/net/ethernet/intel/i40e/i40e_main.c   |  9 ++---
 drivers/net/ethernet/intel/i40e/i40e_txrx.c   |  6 ++--
 drivers/net/ethernet/intel/i40e/i40e_txrx.h   |  3 +-
 7 files changed, 72 insertions(+), 10 deletions(-)

-- 
2.53.0