[dpdk-dev] remove dpdk-pdump pcap file, disk space is not freed

[Yan, Xiaoping (NSB - CN/Hangzhou)]

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.

Best regards
Yan Xiaoping