RE: [PATCH net-next 08/11] net: hns3: add interrupt affinity support for misc interrupt

[Salil Mehta <salil.mehta@huawei.com>]

> From: tanhuazhong
> Sent: Wednesday, July 24, 2019 4:19 AM
> To: davem@davemloft.net
> Cc: netdev@vger.kernel.org; linux-kernel@vger.kernel.org; Salil Mehta
> <salil.mehta@huawei.com>; Zhuangyuzeng (Yisen) <yisen.zhuang@huawei.com>;
> Linuxarm <linuxarm@huawei.com>; linyunsheng <linyunsheng@huawei.com>; lipeng
> (Y) <lipeng321@huawei.com>; tanhuazhong <tanhuazhong@huawei.com>
> Subject: [PATCH net-next 08/11] net: hns3: add interrupt affinity support for
> misc interrupt
> 
> From: Yunsheng Lin <linyunsheng@huawei.com>
> 
> The misc interrupt is used to schedule the reset and mailbox
> subtask, and a 1 sec timer is used to schedule the service
> subtask, which does periodic work.
> 
> This patch sets the above three subtask's affinity using the
> misc interrupt' affinity.
> 
> Also this patch setups a affinity notify for misc interrupt to
> allow user to change the above three subtask's affinity.
> 
> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
> Signed-off-by: Peng Li <lipeng321@huawei.com>
> Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
> ---
>  .../ethernet/hisilicon/hns3/hns3pf/hclge_main.c    | 59
> ++++++++++++++++++++--
>  .../ethernet/hisilicon/hns3/hns3pf/hclge_main.h    |  4 ++
>  2 files changed, 59 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
> b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
> index f345095..fe45986 100644
> --- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
> +++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
> @@ -1270,6 +1270,12 @@ static int hclge_configure(struct hclge_dev *hdev)
> 
>  	hclge_init_kdump_kernel_config(hdev);
> 
> +	/* Set the init affinity based on pci func number */
> +	i = cpumask_weight(cpumask_of_node(dev_to_node(&hdev->pdev->dev)));
> +	i = i ? PCI_FUNC(hdev->pdev->devfn) % i : 0;
> +	cpumask_set_cpu(cpumask_local_spread(i, dev_to_node(&hdev->pdev->dev)),
> +			&hdev->affinity_mask);
> +
>  	return ret;
>  }
> 
> @@ -2502,14 +2508,16 @@ static void hclge_mbx_task_schedule(struct hclge_dev
> *hdev)
>  {
>  	if (!test_bit(HCLGE_STATE_CMD_DISABLE, &hdev->state) &&
>  	    !test_and_set_bit(HCLGE_STATE_MBX_SERVICE_SCHED, &hdev->state))
> -		schedule_work(&hdev->mbx_service_task);
> +		queue_work_on(cpumask_first(&hdev->affinity_mask), system_wq,


Why we have to use system Work Queue here? This could adversely affect
other work scheduled not related to the HNS3 driver. Mailbox is internal
to the driver and depending upon utilization of the mbx channel(which could
be heavy if many VMs are running), this might stress other system tasks
as well. Have we thought of this?



> +			      &hdev->mbx_service_task);
>  }
> 
>  static void hclge_reset_task_schedule(struct hclge_dev *hdev)
>  {
>  	if (!test_bit(HCLGE_STATE_REMOVING, &hdev->state) &&
>  	    !test_and_set_bit(HCLGE_STATE_RST_SERVICE_SCHED, &hdev->state))
> -		schedule_work(&hdev->rst_service_task);
> +		queue_work_on(cpumask_first(&hdev->affinity_mask), system_wq,
> +			      &hdev->rst_service_task);
>  }
> 
>  static void hclge_task_schedule(struct hclge_dev *hdev)
> @@ -2517,7 +2525,8 @@ static void hclge_task_schedule(struct hclge_dev *hdev)
>  	if (!test_bit(HCLGE_STATE_DOWN, &hdev->state) &&
>  	    !test_bit(HCLGE_STATE_REMOVING, &hdev->state) &&
>  	    !test_and_set_bit(HCLGE_STATE_SERVICE_SCHED, &hdev->state))
> -		(void)schedule_work(&hdev->service_task);
> +		queue_work_on(cpumask_first(&hdev->affinity_mask), system_wq,

Same here.


Salil.