From 759dc4a7e605e0dc21708b0a6e0816ed0ac82641 Mon Sep 17 00:00:00 2001 From: Jacob Keller Date: Fri, 14 Jul 2017 09:10:10 -0400 Subject: [PATCH] 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 Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/i40e/i40e_main.c | 12 +++++++----- drivers/net/ethernet/intel/i40evf/i40evf_main.c | 7 +++++-- 2 files changed, 12 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 7366e7c7f399..6498da8806cb 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -2881,7 +2881,7 @@ static void i40e_config_xps_tx_ring(struct i40e_ring *ring) if ((vsi->tc_config.numtc <= 1) && !test_and_set_bit(__I40E_TX_XPS_INIT_DONE, &ring->state)) { netif_set_xps_queue(ring->netdev, - &ring->q_vector->affinity_mask, + get_cpu_mask(ring->q_vector->v_idx), ring->queue_index); } @@ -3506,8 +3506,10 @@ static int i40e_vsi_request_irq_msix(struct i40e_vsi *vsi, char *basename) q_vector->affinity_notify.notify = i40e_irq_affinity_notify; q_vector->affinity_notify.release = i40e_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)); } vsi->irqs_ready = true; @@ -4289,7 +4291,7 @@ static void i40e_vsi_free_irq(struct i40e_vsi *vsi) /* clear the affinity notifier in the IRQ descriptor */ irq_set_affinity_notifier(irq_num, NULL); - /* clear the affinity_mask in the IRQ descriptor */ + /* remove our suggested affinity mask for this IRQ */ irq_set_affinity_hint(irq_num, NULL); synchronize_irq(irq_num); free_irq(irq_num, vsi->q_vectors[i]); @@ -8235,7 +8237,7 @@ static int i40e_vsi_alloc_q_vector(struct i40e_vsi *vsi, int v_idx, int cpu) q_vector->vsi = vsi; q_vector->v_idx = v_idx; - cpumask_set_cpu(cpu, &q_vector->affinity_mask); + cpumask_copy(&q_vector->affinity_mask, cpu_possible_mask); if (vsi->netdev) netif_napi_add(vsi->netdev, &q_vector->napi, diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_main.c b/drivers/net/ethernet/intel/i40evf/i40evf_main.c index 9ee277e87f10..1825d956bb00 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); } -- 2.30.2