Opened 4 years ago

Closed 4 years ago

Last modified 4 years ago

#15641 closed defect (fixed)

virtual SSID causes high load/unresponsiveness/reboots on ath9k with trunk

Reported by: mgondium@… Owned by: developers
Priority: normal Milestone: Barrier Breaker 14.07
Component: packages Version: Trunk
Keywords: trunk, ssid, high load Cc:


Surges of high load averages and SYS % usage on ath9k after creating virtual "guest") SSID.
System becomes unresponsive and randomly reboots when loaded with other tasks (LuCI, ssh login).

Router is a TPLINK 1043ND v1.
Running compiled trunk r44535 with base config + LuCI UI + usb.

top shows "kworker/u2:0" and "hostapd" with 20-30% cpu load,
load average as high as 10, % sys up to 99.

Attachments (3)

config (149.0 KB) - added by mgondium@… 4 years ago.
build configuration
wireless (618 bytes) - added by mgondium@… 4 years ago.
wireless config
trunk_hostpad_crash.png (168.9 KB) - added by mgondium@… 4 years ago.
htop terminal at crash

Download all attachments as: .zip

Change History (11)

Changed 4 years ago by mgondium@…

build configuration

Changed 4 years ago by mgondium@…

wireless config

comment:1 Changed 4 years ago by mgondium@…

The problem appears mitigated by using the full hostapd/wpa-supplicant instead of wpad-mini.
Not sure if scenario is similar but still there are no freeze/reboots.

comment:2 Changed 4 years ago by nbd

please try r40572 (with both -mini and full)

comment:3 Changed 4 years ago by mgondium@…

Full is ok on r40572 + patch 950, I will test -mini now.

comment:4 Changed 4 years ago by mgondium@…

The reboots continue to happen while configuring a guest SSID via LuCI: the system load shoots up, and the system freezes and eventually reboots.

HOWEVER, while testing the full hostapd, I had reboots. Guess I just got lucky before.

Setting a LED to the heartbeat shows an increasing rate, completely stressed for about 30 seconds until the reboot,
so I guess that some kind of watchdog panics and is responsible for the restart.

Free RAM is about 6 MB when starting the process, so I guess it does not run out of memory.

The only way to get the guest SSID configured is to use a configuration file.

However, after configured, I have not experienced the previous freezes while logging in or configuring other aspects.
Connectivity stability looks good too.

Screenshot of htop terminal on the moment of the crash follows.

Changed 4 years ago by mgondium@…

htop terminal at crash

comment:5 Changed 4 years ago by mgondium@…

The crash was while adding the new interface to a firewall zone.

comment:6 Changed 4 years ago by mgondium@…

Tried again after adding some swap space and changing swappiness to 100 for a worst-case-scenario: had no reboots yet.
Swap usage peaked at 3 MB while configuring.
So I guess RAM is starting to get real tight for this device.

comment:7 Changed 4 years ago by nbd

  • Resolution set to fixed
  • Status changed from new to closed

there was a memory leak in mac80211 as well. it's fixed in r40834

comment:8 Changed 4 years ago by jow

  • Milestone changed from Attitude Adjustment 12.09 to Barrier Breaker 14.07

Milestone Attitude Adjustment 12.09 deleted

Add Comment

Modify Ticket

as closed .
The resolution will be deleted. Next status will be 'reopened'.

E-mail address and user name can be saved in the Preferences.

Note: See TracTickets for help on using tickets.