[dpdk-dev] 回复: [PATCH] driver/net/pcap fix: pcap fd leak

[Tengfei Zhang]

On 2021/3/1 下午7:40, Ferruh Yigit wrote:
> Please do not top post, message moved down.
>
> On 2/26/2021 5:47 PM, 张 杨 wrote:
>>> I think your idea is fine
>>>
>>> What do you think just record file path in "pmd_pcap_probe()",
>>>
>>> Perform an open operation only in "eth_dev_start()"?
>>>
>>> When the secondary process add pcap vdev,
>>>
>>> it send the request to primary process,
>>>
>>> the primary process probe pcap vdev too ,
>>>
>>> Both the two process open the same file (in function 
>>> "pmd_pcap_probe()")
>>>
>>> It's not necessary
>>>
>>> I prefer "ZhangTengfei <zypscode at outlook.com>" sign (this one)
>>>
>>> 发送自Windows 10 版邮件 
>>> <https://go.microsoft.com/fwlink/?LinkId=550986>应用
>>>
>>> *发件人: *Ferruh Yigit <mailto:ferruh.yigit at intel.com>
>>> *发送时间: *2021年2月27日0:46
>>> *收件人: *ZhangTengfei <mailto:zypscode at outlook.com>
>>> *抄送: *dev at dpdk.org <mailto:dev at dpdk.org>
>>> *主题: *Re: [PATCH] driver/net/pcap fix: pcap fd leak
>>>
>>> On 2/26/2021 4:20 PM, ZhangTengfei wrote:
>>>> pcap fd was opend when vdev probed,
>>>> but not closed when vdev removed.
>>>> This bug appears in dpdk-pdump
>>>>
>>>> Signed-off-by: ZhangTengfei <zypscode at outlook.com>
>>>> ---
>>>>   drivers/net/pcap/rte_eth_pcap.c | 1 +
>>>>   1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/drivers/net/pcap/rte_eth_pcap.c 
>>>> b/drivers/net/pcap/rte_eth_pcap.c
>>>> index 90f5d75ea..fb01ea924 100644
>>>> --- a/drivers/net/pcap/rte_eth_pcap.c
>>>> +++ b/drivers/net/pcap/rte_eth_pcap.c
>>>> @@ -1597,6 +1597,7 @@ pmd_pcap_remove(struct rte_vdev_device *dev)
>>>>        if (eth_dev == NULL)
>>>>                return 0; /* port already released */
>>>>   +     eth_dev_stop(eth_dev);
>>>>        eth_dev_close(eth_dev);
>>>>        rte_eth_dev_release_port(eth_dev);
>>>>
>>>
>>> Thanks for the fix,
>>> the cleanup seems missing in 'eth_dev_close()' too, what do you 
>>> think moving
>>> 'eth_dev_stop(eth_dev);' inside the 'eth_dev_close()'?
>>> So both 'close' and 'remove' will be covered.
>>>
>>>
>>> Btw, you have same patch with both "ZhangTengfei 
>>> <zhangtengfei at oppo.com>" sign
>>> and "ZhangTengfei <zypscode at outlook.com>" sign (this one), can you 
>>> please
>>> clarify which one do you prefer?
>>>
> >
> > I think your idea is fine
> >
> > What do you think just record file path in "pmd_pcap_probe()",
> > Perform an open operation only in "eth_dev_start()"?
> >
> > When the secondary process add pcap vdev,
> > it send the request to primary process,
> > the primary process probe pcap vdev too ,>
> > Both the two process open the same file (in function 
> "pmd_pcap_probe()")
> > It's not necessary
> >
>
> Opening pcap helps us fail early in probe() if something is wrong, 
> otherwise the driver probed and the problem detected in the start() 
> when it is too late.
> start() also opens pcap if it is not already opened.
>
> In your usecase, if the pcap added by the secondary with the intention 
> to use only by the secondary, yes primary process also opens the pcap 
> unnecessarily, but that shouldn't be really a concern, this is one 
> time cost in probe().
>
> > I prefer "ZhangTengfei <zypscode at outlook.com>" sign (this one)
>
> OK, also can you please use "Name Surname <email at address.com>" format, 
> to be consistent, I guess for you it means as following:
> Tengfei Zhang <zypscode at outlook.com>

Rarely submit code to the open source community. Thank you for your advice.

I quite agree with your  view "fail early".

I will update the patch