title: fsl_dpa NIC memory leak?
body: <p>I encountered a memory leak issue which led to system crash。
  Analyzing vmcore, found that there are so many skb(list as below) not freed.</p>
  <pre><code>crash&gt; kmem -s |grep  skbuff_head_cache
  ffff80007b2a0c00      256     426183    426416  26651     4k  skbuff_head_cache
  </code></pre>
  <p>most of them are multicast or broadcast packets.
  most of them are on eth4.</p>
  <pre><code>crash&gt; sk_buff.dev -x ffff8000095a5500
          dev = 0xffff800063129000
  crash&gt; net
     NET_DEVICE     NAME   IP ADDRESS(ES)
  ffff80007b2ca000  lo     127.0.0.1
  ffff800063124000  eth0   
  ffff80007b2c0000  eth1   192.168.1.4
  ffff800063126000  eth2   
  ffff80006362d000  eth3   169.254.200.1
  ffff800063129000  eth4 
  </code></pre>
  <p>NIC information</p>
  <pre><code>[root@localhost ~]# ethtool -i eth4
  driver: fsl_dpa
  version: 
  firmware-version: 0
  expansion-rom-version: 
  bus-info: soc:fsl,dpaa
  supports-statistics: yes
  supports-test: no
  supports-eeprom-access: no
  supports-register-dump: no
  supports-priv-flags: no
  </code></pre>
  <p>second time, I found that the leaked packets could be freed by DOWN/UP the NIC eth4.</p>
  <pre><code>[root@localhost log]# cat /proc/slabinfo |grep skbuff_head;date
  skbuff_head_cache 246636 247424    256   16    1 : tunables  120   60    8 : slabdata  15464  15464    120
  2021年 09月 15日 星期三 13:50:51 CST
  [root@localhost log]# ifconfig eth4 up
  [root@localhos log]# cat /proc/slabinfo |grep skbuff_head;date
  skbuff_head_cache   3516  14528    256   16    1 : tunables  120   60    8 : slabdata    908    908    420
  2021年 09月 15日 星期三 13:50:58 CST
  </code></pre>
  <p>Anyone who can help me to diagnose it is very appreciate.</p>