i40e: initialize our affinity_mask based on cpu_possible_mask
On older kernels a call to irq_set_affinity_hint does not guarantee that
the IRQ affinity will be set. If nothing else on the system sets the IRQ
affinity this can result in a bug in the i40e_napi_poll() routine where
we notice that our interrupt fired on the "wrong" CPU according to our
internal affinity_mask variable.
This results in a bug where we continuously tell NAPI to stop polling to
move the interrupt to a new CPU, but the CPU never changes because our
affinity mask does not match the actual mask setup for the IRQ.
The root problem is a mismatched affinity mask value. So lets initialize
the value to cpu_possible_mask instead. This ensures that prior to the
first time we get an IRQ affinity notification we'll have the mask set
to include every possible CPU.
We use cpu_possible_mask instead of cpu_online_mask since the former is
almost certainly never going to change, while the later might change
after we've made a copy.
Signed-off-by: Jacob Keller <jacob.e.keller@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 9ee277e..1825d95 100644
--- a/drivers/net/ethernet/intel/i40evf/i40evf_main.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
@@ -584,8 +584,10 @@ i40evf_request_traffic_irqs(struct i40evf_adapter *adapter, char *basename)
q_vector->affinity_notify.release =
i40evf_irq_affinity_release;
irq_set_affinity_notifier(irq_num, &q_vector->affinity_notify);
- /* assign the mask for this irq */
- irq_set_affinity_hint(irq_num, &q_vector->affinity_mask);
+ /* get_cpu_mask returns a static constant mask with
+ * a permanent lifetime so it's ok to use here.
+ */
+ irq_set_affinity_hint(irq_num, get_cpu_mask(q_vector->v_idx));
}
return 0;
@@ -1456,6 +1458,7 @@ static int i40evf_alloc_q_vectors(struct i40evf_adapter *adapter)
q_vector->adapter = adapter;
q_vector->vsi = &adapter->vsi;
q_vector->v_idx = q_idx;
+ cpumask_copy(&q_vector->affinity_mask, cpu_possible_mask);
netif_napi_add(adapter->netdev, &q_vector->napi,
i40evf_napi_poll, NAPI_POLL_WEIGHT);
}