Re: -current network buffer exhaustion on RPi2 armv7

On Mon, Feb 16, 2026 at 03:55:56PM -0800, Adrian Chadd wrote:
> On Mon, 16 Feb 2026 at 15:30, bob prohaska <[email protected]> wrote:
> >
> > Oops, I'm mistaken. The network connection turned out to be down.
> > However, the system didn't seem to know it. ifconfig reported:
> > lan0: flags=8c43<UP,BROADCAST,RUNNING,DRV_OACTIVE,SIMPLEX,MULTICAST> metric 0 mtu 1500
> >         options=0
> >         ether 00:0f:60:05:37:4f
> >         inet 192.168.1.10 netmask 0xffffff00 broadcast 192.168.1.255
> >         inet6 fe80::20f:60ff:fe05:374f%wlan0 prefixlen 64 scopeid 0x3
> >         groups: wlan
> >         ssid "" channel 2 (2417 MHz 11g)
> >         regdomain ETSI2 country US authmode WPA1+WPA2/802.11i privacy ON
> >         deftxkey UNDEF txpower 30 bmiss 7 scanvalid 60 protmode CTS wme
> >         roaming MANUAL
> >         parent interface: run0
> >         media: IEEE 802.11 Wireless Ethernet DS/1Mbps mode 11g (autoselect)
> >         status: no carrier
> >         nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>
> 
> > but ping reported network is down. Running ifconfig wlan0 up provoked
> > no response and no change in behavior. Running ifconfig wlan0 down
> > reports dhclient exiting, followed by
> > ifconfig wlan0 up seems to restore connectivity, at least for a while.
> >
> > Is the system losing its connectivity and not noticing? Or maybe
> > noticing but getting stuck in a loop trying to recover? The
> > status: no carrier
> > seems to indicate a problem.
> 
> Yup, it looks like for some reason it's hung; wpa_supplicant should be
> kicking off a scan and well,
> the above is telling me that it is stuck.
> 
> Try running "wpa_cli" to see what decisions its making. it logs them
> to the wpa_cli tool whilst its running.
> You may first need to put this in /etc/wpa_supplicant.conf :
> 
> ctrl_interface=/var/run/wpa_supplicant
> 
> Meanwhile I'll go test out that NIC in a test device as its primary
> internet connection and report back.

With wpa_cli running on the serial console for most of a day there appeared:


root@generic:/usr/src # wpa_cli
wpa_cli v2.11
Copyright (c) 2004-2024, Jouni Malinen <[email protected]> and contributors

This software may be distributed under the terms of the BSD license.
See README for more details.


Selected interface 'wlan0'

Interactive mode

<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>CTRL-EVENT-DISCONNECTED bssid=00:13:46:86:6d:0c reason=1 locally_generated=1
<3>Added BSSID 00:13:46:86:6d:0c into ignore list, ignoring for 10 seconds
<3>CTRL-EVENT-DSCP-POLICY clear_all
> Feb 18 14:33:38 generic syslogd: last message repeated 1 times
<3>CTRL-EVENT-SCAN-RESULTS 
<3>WPS-AP-AVAILABLE 
<3>Removed BSSID 00:13:46:86:6d:0c from ignore list (clear)
<3>Trying to associate with 00:13:46:86:6d:0c (SSID='d-link.zefox.net' freq=2417 MHz)
<3>Associated with 00:13:46:86:6d:0c
<3>WPA: Key negotiation completed with 00:13:46:86:6d:0c [PTK=CCMP GTK=TKIP]
<3>CTRL-EVENT-CONNECTED - Connection to 00:13:46:86:6d:0c completed [id=0 id_str=]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
<3>RSN: Group rekeying completed with 00:13:46:86:6d:0c [GTK=TKIP]
 

I don't see any complaints about buffers on the console and 
after quitting wpa_cli both ping and ifconfig agreed the network
was up and running. It's unfortunate there are no timestamps,
I'd guess the events above represent about six hours. The host
was running buildworld with -j4. At the time of reporting this
buildworld hadn't reached the point of maximum swap activity.

If there's some trick for making wpa_cli run in the background
and log output to a file that would be very helpful.

Thanks for reading,

bob prohaska