> -----Original Message-----
> From: Zhang, RobinX <robinx.zh...@intel.com>
> Sent: Friday, July 23, 2021 3:47 PM
> To: dev@dpdk.org
> Cc: Wu, Jingjing <jingjing...@intel.com>; Xing, Beilei
> <beilei.x...@intel.com>;
> Zhang, Qi Z <qi.z.zh...@intel.com>; Guo, Junfeng <junfeng....@intel.com>;
> Yang, SteveX <stevex.y...@intel.com>; Zhang, RobinX
> <robinx.zh...@intel.com>
> Subject: [PATCH] net/iavf: remove interrupt handler
As you are not going to remove interrupt handler for all the cases, the title
is misleading
Better replace it with "enable interrupt polling"
>
> For VF hosted by Intel 700 series NICs, internal rx interrupt and adminq
> interrupt share the same source, that cause a lot cpu cycles be wasted on
> interrupt handler on rx path.
>
> The patch disable pci interrupt and remove the interrupt handler, replace it
> with a low frequency(50ms) interrupt polling daemon which is implemtented by
> registering an alarm callback periodly.
>
> The virtual channel capability bit VIRTCHNL_VF_OFFLOAD_WB_ON_ITR can be
> used to negotiate if iavf PMD needs to enable background alarm or not, so
> ideally this change will not impact the case hosted by Intel 800 series NICS.
>
> Suggested-by: Jingjing Wu <jingjing...@intel.com>
> Signed-off-by: Qi Zhang <qi.z.zh...@intel.com>
No need to add me as the author for this patch but, you can add a reference to
the original i40e commit to explain you implement the same logic.
> Signed-off-by: Robin Zhang <robinx.zh...@intel.com>
> ---
> drivers/net/iavf/iavf.h | 3 +++
> drivers/net/iavf/iavf_ethdev.c | 37 ++++++++++++++--------------------
> drivers/net/iavf/iavf_vchnl.c | 11 ++++------
> 3 files changed, 22 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/net/iavf/iavf.h b/drivers/net/iavf/iavf.h index
> b3bd078111..771f3b79d7 100644
> --- a/drivers/net/iavf/iavf.h
> +++ b/drivers/net/iavf/iavf.h
> @@ -69,6 +69,8 @@
> #define IAVF_QUEUE_ITR_INTERVAL_DEFAULT 32 /* 32 us */
> #define IAVF_QUEUE_ITR_INTERVAL_MAX 8160 /* 8160 us */
>
> +#define IAVF_ALARM_INTERVAL 50000 /* us */
> +
> /* The overhead from MTU to max frame size.
> * Considering QinQ packet, the VLAN tag needs to be counted twice.
> */
> @@ -372,6 +374,7 @@ int iavf_config_irq_map_lv(struct iavf_adapter
> *adapter, uint16_t num, void iavf_add_del_all_mac_addr(struct iavf_adapter
> *adapter, bool add); int iavf_dev_link_update(struct rte_eth_dev *dev,
> __rte_unused int wait_to_complete);
> +void iavf_dev_alarm_handler(void *param);
> int iavf_query_stats(struct iavf_adapter *adapter,
> struct virtchnl_eth_stats **pstats); int
> iavf_config_promisc(struct iavf_adapter *adapter, bool enable_unicast, diff
> --git a/drivers/net/iavf/iavf_ethdev.c b/drivers/net/iavf/iavf_ethdev.c index
> 41382c6d66..bbe5b3ddb1 100644
> --- a/drivers/net/iavf/iavf_ethdev.c
> +++ b/drivers/net/iavf/iavf_ethdev.c
> @@ -16,6 +16,7 @@
> #include <rte_interrupts.h>
> #include <rte_debug.h>
> #include <rte_pci.h>
> +#include <rte_alarm.h>
> #include <rte_atomic.h>
> #include <rte_eal.h>
> #include <rte_ether.h>
> @@ -692,9 +693,9 @@ static int iavf_config_rx_queues_irqs(struct
> rte_eth_dev *dev,
> */
> vf->msix_base = IAVF_MISC_VEC_ID;
>
> - /* set ITR to max */
> + /* set ITR to default */
> interval = iavf_calc_itr_interval(
> - IAVF_QUEUE_ITR_INTERVAL_MAX);
> + IAVF_QUEUE_ITR_INTERVAL_DEFAULT);
> IAVF_WRITE_REG(hw, IAVF_VFINT_DYN_CTL01,
> IAVF_VFINT_DYN_CTL01_INTENA_MASK |
> (IAVF_ITR_INDEX_DEFAULT <<
> @@ -853,9 +854,8 @@ iavf_dev_start(struct rte_eth_dev *dev)
> PMD_DRV_LOG(ERR, "configure irq failed");
> goto err_queue;
> }
> - /* re-enable intr again, because efd assign may change */
> + /* only enable interrupt in rx interrupt mode */
> if (dev->data->dev_conf.intr_conf.rxq != 0) {
> - rte_intr_disable(intr_handle);
> rte_intr_enable(intr_handle);
> }
>
> @@ -889,6 +889,9 @@ iavf_dev_stop(struct rte_eth_dev *dev)
>
> PMD_INIT_FUNC_TRACE();
>
> + if (dev->data->dev_conf.intr_conf.rxq != 0)
> + rte_intr_disable(intr_handle);
> +
> if (adapter->stopped == 1)
> return 0;
>
> @@ -1669,8 +1672,6 @@ iavf_dev_rx_queue_intr_enable(struct rte_eth_dev
> *dev, uint16_t queue_id)
>
> IAVF_WRITE_FLUSH(hw);
>
> - rte_intr_ack(&pci_dev->intr_handle);
> -
> return 0;
> }
>
> @@ -2201,8 +2202,8 @@ iavf_disable_irq0(struct iavf_hw *hw)
> IAVF_WRITE_FLUSH(hw);
> }
>
> -static void
> -iavf_dev_interrupt_handler(void *param)
> +void
> +iavf_dev_alarm_handler(void *param)
> {
> struct rte_eth_dev *dev = (struct rte_eth_dev *)param;
> struct iavf_hw *hw =
> IAVF_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> @@ -2212,6 +2213,9 @@ iavf_dev_interrupt_handler(void *param)
> iavf_handle_virtchnl_msg(dev);
>
> iavf_enable_irq0(hw);
> +
> + rte_eal_alarm_set(IAVF_ALARM_INTERVAL,
> + iavf_dev_alarm_handler, dev);
> }
>
> static int
> @@ -2314,13 +2318,8 @@ iavf_dev_init(struct rte_eth_dev *eth_dev)
> rte_ether_addr_copy((struct rte_ether_addr *)hw->mac.addr,
> ð_dev->data->mac_addrs[0]);
>
> - /* register callback func to eal lib */
> - rte_intr_callback_register(&pci_dev->intr_handle,
> - iavf_dev_interrupt_handler,
> - (void *)eth_dev);
> -
> - /* enable uio intr after callback register */
> - rte_intr_enable(&pci_dev->intr_handle);
> + rte_eal_alarm_set(IAVF_ALARM_INTERVAL,
> + iavf_dev_alarm_handler, eth_dev);
>
> /* configure and enable device interrupt */
> iavf_enable_irq0(hw);
> @@ -2341,7 +2340,6 @@ iavf_dev_close(struct rte_eth_dev *dev) {
> struct iavf_hw *hw =
> IAVF_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> struct rte_pci_device *pci_dev = RTE_ETH_DEV_TO_PCI(dev);
> - struct rte_intr_handle *intr_handle = &pci_dev->intr_handle;
> struct iavf_adapter *adapter =
> IAVF_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
> struct iavf_info *vf =
> IAVF_DEV_PRIVATE_TO_VF(dev->data->dev_private);
> @@ -2364,12 +2362,7 @@ iavf_dev_close(struct rte_eth_dev *dev)
> iavf_config_promisc(adapter, false, false);
>
> iavf_shutdown_adminq(hw);
> - /* disable uio intr before callback unregister */
> - rte_intr_disable(intr_handle);
> -
> - /* unregister callback func from eal lib */
> - rte_intr_callback_unregister(intr_handle,
> - iavf_dev_interrupt_handler, dev);
> + rte_eal_alarm_cancel(iavf_dev_alarm_handler, dev);
> iavf_disable_irq0(hw);
>
> if (vf->vf_res->vf_cap_flags & VIRTCHNL_VF_OFFLOAD_QOS) diff --git
> a/drivers/net/iavf/iavf_vchnl.c b/drivers/net/iavf/iavf_vchnl.c index
> 06dc663947..af19dd6412 100644
> --- a/drivers/net/iavf/iavf_vchnl.c
> +++ b/drivers/net/iavf/iavf_vchnl.c
> @@ -13,6 +13,7 @@
> #include <rte_common.h>
>
> #include <rte_debug.h>
> +#include <rte_alarm.h>
> #include <rte_atomic.h>
> #include <rte_eal.h>
> #include <rte_ether.h>
> @@ -1663,7 +1664,6 @@ iavf_request_queues(struct iavf_adapter *adapter,
> uint16_t num) {
> struct rte_eth_dev *dev = adapter->eth_dev;
> struct iavf_info *vf = IAVF_DEV_PRIVATE_TO_VF(adapter);
> - struct rte_pci_device *pci_dev = RTE_ETH_DEV_TO_PCI(dev);
> struct virtchnl_vf_res_request vfres;
> struct iavf_cmd_info args;
> uint16_t num_queue_pairs;
> @@ -1687,13 +1687,10 @@ iavf_request_queues(struct iavf_adapter
> *adapter, uint16_t num)
> args.out_buffer = vf->aq_resp;
> args.out_size = IAVF_AQ_BUF_SZ;
>
> - /*
> - * disable interrupt to avoid the admin queue message to be read
> - * before iavf_read_msg_from_pf.
> - */
> - rte_intr_disable(&pci_dev->intr_handle);
> + rte_eal_alarm_cancel(iavf_dev_alarm_handler, dev);
> err = iavf_execute_vf_cmd(adapter, &args);
> - rte_intr_enable(&pci_dev->intr_handle);
> + rte_eal_alarm_set(IAVF_ALARM_INTERVAL,
> + iavf_dev_alarm_handler, dev);
> if (err) {
> PMD_DRV_LOG(ERR, "fail to execute command
> OP_REQUEST_QUEUES");
> return err;
> --
> 2.25.1
