i40e/i40evf: adjust interrupt throttle less frequently
The adaptive ITR (interrupt throttle rate) algorithm was adjusting
the hardware's interrupt rate too frequently. This caused a lot
of variation in the interrupt rate for fairly constant workloads.
Change the code to have a counter and adjust only once every N
number of interrupts.
Change-ID: I0460f1f86571037484eca5aca36ac4d889cb8389
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_main.c b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
index ce99790..a44a42b 100644
--- a/drivers/net/ethernet/intel/i40evf/i40evf_main.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
@@ -357,6 +357,7 @@
q_vector->rx.ring = rx_ring;
q_vector->rx.count++;
q_vector->rx.latency_range = I40E_LOW_LATENCY;
+ q_vector->itr_countdown = ITR_COUNTDOWN_START;
}
/**
@@ -377,6 +378,7 @@
q_vector->tx.ring = tx_ring;
q_vector->tx.count++;
q_vector->tx.latency_range = I40E_LOW_LATENCY;
+ q_vector->itr_countdown = ITR_COUNTDOWN_START;
q_vector->num_ringpairs++;
q_vector->ring_mask |= BIT(t_idx);
}