[dpdk-dev] [PATCH 4/5] net/ixgbevf: add check for rte_intr_enable.

[Tonghao Zhang]

On Thu, Jan 11, 2018 at 3:06 PM, Xing, Beilei <beilei.xing at intel.com> wrote:
>
>
>> -----Original Message-----
>> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Tonghao Zhang
>> Sent: Friday, January 5, 2018 10:11 PM
>> To: dev at dpdk.org
>> Cc: Tonghao Zhang <xiangxia.m.yue at gmail.com>
>> Subject: [dpdk-dev] [PATCH 4/5] net/ixgbevf: add check for rte_intr_enable.
>
> The patch is not only for ixgbevf, but also for ixgbe, right?
> so how about changing the title with net/ixgbe started?
>
OK

>> When we bind the ixgbevf to vfio and call the rte_eth_dev_rx_intr_enable
>> and rte_eth_dev_rx_intr_disable frequently, the interrupt setting
>> (msi_set_mask_bit) will take more CPU as show below. rte_intr_enable call
>> the ioctl to map the fd to interrupts frequently.
>>
>> perf top:
>> 5.45%  [kernel]   [k] msi_set_mask_bit
>>
>> It is unnecessary to call the rte_intr_enable in
>> ixgbe_dev_rx_queue_intr_enable. because the fds has been mapped to
>> interrupt and not unmapped in ixgbe_dev_rx_queue_intr_disable.
>>
>> This patch add checks for using VFIO.  With the patch, msi_set_mask_bit is
>> not listed in perl any more. Any suggestion will be welcome.
>>
>> Signed-off-by: Tonghao Zhang <xiangxia.m.yue at gmail.com>
>> ---
>>  drivers/net/ixgbe/ixgbe_ethdev.c | 9 +++++++--
>>  1 file changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c
>> b/drivers/net/ixgbe/ixgbe_ethdev.c
>> index e929235..79e4097 100644
>> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
>> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
>> @@ -5610,7 +5610,9 @@ static void ixgbevf_set_vfta_all(struct rte_eth_dev
>> *dev, bool on)
>>       RTE_SET_USED(queue_id);
>>       IXGBE_WRITE_REG(hw, IXGBE_VTEIMS, intr->mask);
>>
>> -     rte_intr_enable(intr_handle);
>> +     if (intr_handle->type == RTE_INTR_HANDLE_UIO ||
>> +         intr_handle->type == RTE_INTR_HANDLE_UIO_INTX)
>> +             rte_intr_enable(intr_handle);
>
> For igb_uio, did you check if it's necessary to call rte_intr_enable every time? Since rte interrupt is not disabled during ixgbevf_dev_rx_queue_intr_disable.

good, remove the rte_intr_enable directly, because intr has been
disable/enable via writing the register in
ixgbevf_dev_rx_queue_intr_disable/enable.
>>
>>       return 0;
>>  }
>> @@ -5659,7 +5661,10 @@ static void ixgbevf_set_vfta_all(struct
>> rte_eth_dev *dev, bool on)
>>               mask &= (1 << (queue_id - 32));
>>               IXGBE_WRITE_REG(hw, IXGBE_EIMS_EX(1), mask);
>>       }
>> -     rte_intr_enable(intr_handle);
>> +
>> +     if (intr_handle->type == RTE_INTR_HANDLE_UIO ||
>> +         intr_handle->type == RTE_INTR_HANDLE_UIO_INTX)
>> +             rte_intr_enable(intr_handle);
>
> The same comment as above.
>
>>
>>       return 0;
>>  }
>> --
>> 1.8.3.1
>