qlcnic: remove ndo_poll_controller

As diagnosed by Song Liu, ndo_poll_controller() can
be very dangerous on loaded hosts, since the cpu
calling ndo_poll_controller() might steal all NAPI
contexts (for all RX/TX queues of the NIC). This capture
can last for unlimited amount of time, since one
cpu is generally not able to drain all the queues under load.

qlcnic uses NAPI for TX completions, so we better let core
networking stack call the napi->poll() to avoid the capture.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Harish Patil <harish.patil@cavium.com>
Cc: Manish Chopra <manish.chopra@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2018-09-27 09:31:56 -07:00 committed by David S. Miller
parent 260dd2c3e2
commit 81b059b218
1 changed files with 0 additions and 45 deletions

View File

@ -59,9 +59,6 @@ static int qlcnic_close(struct net_device *netdev);
static void qlcnic_tx_timeout(struct net_device *netdev);
static void qlcnic_attach_work(struct work_struct *work);
static void qlcnic_fwinit_work(struct work_struct *work);
#ifdef CONFIG_NET_POLL_CONTROLLER
static void qlcnic_poll_controller(struct net_device *netdev);
#endif
static void qlcnic_idc_debug_info(struct qlcnic_adapter *adapter, u8 encoding);
static int qlcnic_can_start_firmware(struct qlcnic_adapter *adapter);
@ -545,9 +542,6 @@ static const struct net_device_ops qlcnic_netdev_ops = {
.ndo_udp_tunnel_add = qlcnic_add_vxlan_port,
.ndo_udp_tunnel_del = qlcnic_del_vxlan_port,
.ndo_features_check = qlcnic_features_check,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = qlcnic_poll_controller,
#endif
#ifdef CONFIG_QLCNIC_SRIOV
.ndo_set_vf_mac = qlcnic_sriov_set_vf_mac,
.ndo_set_vf_rate = qlcnic_sriov_set_vf_tx_rate,
@ -3200,45 +3194,6 @@ static irqreturn_t qlcnic_msix_tx_intr(int irq, void *data)
return IRQ_HANDLED;
}
#ifdef CONFIG_NET_POLL_CONTROLLER
static void qlcnic_poll_controller(struct net_device *netdev)
{
struct qlcnic_adapter *adapter = netdev_priv(netdev);
struct qlcnic_host_sds_ring *sds_ring;
struct qlcnic_recv_context *recv_ctx;
struct qlcnic_host_tx_ring *tx_ring;
int ring;
if (!test_bit(__QLCNIC_DEV_UP, &adapter->state))
return;
recv_ctx = adapter->recv_ctx;
for (ring = 0; ring < adapter->drv_sds_rings; ring++) {
sds_ring = &recv_ctx->sds_rings[ring];
qlcnic_disable_sds_intr(adapter, sds_ring);
napi_schedule(&sds_ring->napi);
}
if (adapter->flags & QLCNIC_MSIX_ENABLED) {
/* Only Multi-Tx queue capable devices need to
* schedule NAPI for TX rings
*/
if ((qlcnic_83xx_check(adapter) &&
(adapter->flags & QLCNIC_TX_INTR_SHARED)) ||
(qlcnic_82xx_check(adapter) &&
!qlcnic_check_multi_tx(adapter)))
return;
for (ring = 0; ring < adapter->drv_tx_rings; ring++) {
tx_ring = &adapter->tx_ring[ring];
qlcnic_disable_tx_intr(adapter, tx_ring);
napi_schedule(&tx_ring->napi);
}
}
}
#endif
static void
qlcnic_idc_debug_info(struct qlcnic_adapter *adapter, u8 encoding)
{