(Please avoid top-post, I have updated the order of the messages. Please find
the reply at the bottom of the email.)
>> -----Original Message-----
>> From: Ferruh Yigit <ferruh.yi...@intel.com>
>> Sent: 2021年8月23日 18:04
>> To: Yan, Xiaoping (NSB - CN/Hangzhou) <xiaoping....@nokia-sbell.com>;
>> dev@dpdk.org
>> Cc: Reshma Pattan <reshma.pat...@intel.com>
>> Subject: Re: [dpdk-dev] remove dpdk-pdump pcap file, disk space is not freed
>>
>> On 8/23/2021 5:14 AM, Yan, Xiaoping (NSB - CN/Hangzhou) wrote:
>>> Hi,
>>>
>>> Before I run pdump, 21MB is used in /tmp
>>> tmpfs 63G 21M 63G 1% /tmp
>>> Then I run pdump with such command:
>>> dpdk-pdump -c 0x4001000400100 -a 0000:03:00.6 -a 0000:03:06.1
>>> --legacy-mem --base-virtaddr 0x2aaa2aa000 --file-prefix l2rt --
>>> --pdump
>>> port=1,queue=*,rx-dev=/tmp/l2biprt.pcap,tx-dev=/tmp/l2biprt.pcap,mbuf-
>>> size=10240,total-num-mbufs=10000
>>> After stop, it generates a 14MB file
>>> -rw-rw-r--. 1 9999 9999 14M Aug 23 03:58 l2biprt.pcap
>>> And 35M is used in /tmp
>>> tmpfs 63G 35M 63G 1% /tmp
>>> And fuser show there are still several users of this file. (all these pids
>>> are of running dpdk primary and secondary processes )
>>> # fuser /tmp/l2biprt.pcap
>>> /tmp/l2biprt.pcap: 139 342 347 434
>>> Then after I rm the file (l2biprt.pcap), disk space in tmp is not freed
>>> (still 35MB used)
>>> rm l2biprt.pcap
>>> df -h
>>> tmpfs 63G 35M 63G 1% /tmp
>>>
>>>
>>> It seems it goes like this:
>>> pdump start->pdump send vdev hotplug add request->primary and
>>> secondary process calls pmd_pcap_probe() which opens the pcap file->
>>> pdump stop-> pdump send vdev hotplug remove request->
>>> primary and secondary process does not close the pcap file
>>>
>>> To properly close the pcap file and release disk space, it seems we should:
>>>
>>> * somehow close the pcap file in "vdev hotplug remove", or
>>> * don't open the pcap file in "vdev hotplug add"( pmd_pcap_probe()), it
>>> seems pcap eth_dev_start will open the pcap file in case it was not opened.
>>>
>>> Any comment is appreciated, thank you.
>>
>>
>> Hi Yan,
>>
>> I can't reproduce the behavior you mentioned, for my case the .pcap file is
>> closed when pdump is terminated and there is no active user of the file
>> after that point.
>>
>> Removing the pcap device cause closing the .pcap files.
>>
>> When you terminate pdump application it will remove the pcap devices, and
>> since it is a secondary process a message sent to primary to remove it too,
>> making both process closing the pcap files.
>>
>> When I use testpmd as primary application, I am getting following log from
>> testpmd when pdump terminated:
>> "Port 2 is closed"
>> Can you please test with testpmd? You can use '--log-level=*:debug' eal
>> parameter to get more log for multi process communication.
>>
>> Btw, what is your DPDK version? I tested with latest DPDK (21.11.0-rc0).
>>
>>
> On 8/24/2021 8:36 AM, Yan, Xiaoping (NSB - CN/Hangzhou) wrote:
> Hi,
>
> I'm using dpdk 20.11. (it's a bit difficult for me to upgrade my applications
> to latest dpdk)
>
> I tested dpdk-pdump with dpdk-tespmd, result is same (disk space not freed.)
> [root@up-0:/]
> # ps aux
> USER PID %CPU %MEM VSZ RSS TTY STAT START TIME
> COMMAND
> root 78 99.1 0.0 67407568 102268 pts/0 SLl+ 07:15 2:32
> dpdk-testpmd --base-virtaddr 0
> root 144 0.3 0.0 67332948 7708 pts/1 Sl+ 07:17 0:00
> dpdk-pdump -l 14 -a 0000:b3:02
>
> # fuser /tmp/l2biprt.pcap
> /tmp/l2biprt.pcap: 78 144
>
> When stop pdump, indeed testpmd prints:
> EAL: msg: eal_dev_mp_request
> eth_dev_close(): Closing pcap ethdev on NUMA socket 0
> Port 1 is closed
> EAL: reply: eal_dev_mp_request
> But testpmd does not close the file:
> [root@up-0:/]
> # fuser /tmp/l2biprt.pcap
> /tmp/l2biprt.pcap: 78
>
> And remove the pcap file, disk space is not freed:
> # df -h /tmp/
> Filesystem Size Used Avail Use% Mounted on
> tmpfs 94G 900K 94G 1% /tmp
> [root@up-0:/]
> # ls -lh /tmp/
> total 900K
> -rw-r--r--. 1 root root 897K Aug 24 07:18 l2biprt.pcap
> drwxrwxrwx. 2 root root 18 Aug 24 07:14 nes
> [root@up-0:/]
> # rm /tmp/l2biprt.pcap
> [root@up-0:/]
> # ls -lh /tmp/
> total 0
> drwxrwxrwx. 2 root root 18 Aug 24 07:14 nes
> [root@up-0:/]
> # df -h /tmp/
> Filesystem Size Used Avail Use% Mounted on
> tmpfs 94G 900K 94G 1% /tmp
>
> Could you please kindly check the same for your test?
> It seems the testpmd close pcap device via pmd_pcap_remove(), but
> pcap_dump_close is not called.
> Could you please kindly help to check how testpmd in your case close the pcap
> file (if possible with function call stack?)?
>
> Thank you.
>
>
I can reproduce the issue with v20.11. The problems seems fixed by commit [1] in
the latest DPDK, the commit title gives the hint ;)
Backporting that commit can solve the issue.
Regards,
ferruh
[1]
Fixes: e412a138db91 ("net/pcap: fix file descriptor leak on close")
