[FS#303] ZBT-WG3526 - SQM - kernel error - rcu_sched detected stalls on

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - camel (camel) 

Attached to Project - LEDE Project
Summary - ZBT-WG3526 - SQM - kernel error - rcu_sched detected stalls on
Task Type - Bug Report
Category - Base system
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Low
Priority - Very Low
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details - SUBJECT:ZBT-WG3526 - SQM - kernel error - rcu_sched detected stalls on CPUs/tasks:

if I'm using SQM (only on 1 interface)
and i produce a little bit traffic, then kernel CPU stall ... 

Wed Nov 23 21:52:21 2016 kern.err kernel: [ 4922.040000] INFO: rcu_sched detected stalls on CPUs/tasks:
Wed Nov 23 21:52:21 2016 kern.err kernel: [ 4922.040000]        3-...: (0 ticks this GP) idle=15e/0/0 softirq=344657/344657 fqs=0
Wed Nov 23 21:52:21 2016 kern.err kernel: [ 4922.050000]        (detected by 1, t=6003 jiffies, g=115679, c=115678, q=2555)
Wed Nov 23 21:52:21 2016 kern.info kernel: [ 4922.050000] Task dump for CPU 3:
Wed Nov 23 21:52:21 2016 kern.info kernel: [ 4922.060000] swapper/3       R running      0     0      1 0x00100000
Wed Nov 23 21:52:21 2016 kern.warn kernel: [ 4922.060000] Stack : 00000000 e6f1fad4 00000479 ffffffff 000003f1 00000000 804ca2a4 80480000
Wed Nov 23 21:52:21 2016 kern.warn kernel: [ 4922.060000]         8048075c 00000001 00000001 80480680 80480724 80480000 000010d9 8001351c
Wed Nov 23 21:52:21 2016 kern.warn kernel: [ 4922.060000]         00000000 00000003 8fc64000 8fc65ec0 80480000 8005db90 1100fc03 00000003
Wed Nov 23 21:52:21 2016 kern.warn kernel: [ 4922.060000]         00000000 80480000 804ca2a4 8005db88 80480000 8001b014 1100fc03 00000000
Wed Nov 23 21:52:21 2016 kern.warn kernel: [ 4922.060000]         00000004 804804a0 000000a0 8001b01c fbf9d5f7 f3f3fb57 ff7afd7e bfffaeff
Wed Nov 23 21:52:21 2016 kern.warn kernel: [ 4922.060000]         ...
Wed Nov 23 21:52:21 2016 kern.warn kernel: [ 4922.100000] Call Trace:
Wed Nov 23 21:52:21 2016 kern.warn kernel: [ 4922.100000] [] __schedule+0x574/0x758
Wed Nov 23 21:52:21 2016 kern.warn kernel: [ 4922.110000] [] r4k_wait_irqoff+0x0/0x20
Wed Nov 23 21:52:21 2016 kern.warn kernel: [ 4922.110000]
Wed Nov 23 21:52:21 2016 kern.err kernel: [ 4922.110000] rcu_sched kthread starved for 6009 jiffies! g115679 c115678 f0x0 s3 ->state=0x1


#sqm config:
config queue 'eth1'
	option qdisc 'fq_codel'
	option script 'simple.qos'
	option qdisc_advanced '0'
	option linklayer 'none'
	option interface '3g-4G'
	option download '33000'
	option upload '5000'
	option debug_logging '0'
	option verbosity '10'
	option enabled '1'


installed:
#root at router:~#  opkg install luci-app-sqm
#Installing luci-app-sqm (1.0.9-1) to root...
#Downloading http://downloads.lede-project.org/snapshots/packages/mipsel_24kc/packages/luci-app-sqm_1.0.9-1_all.ipk.
#Installing sqm-scripts (1.0.9-1) to root...
#Downloading http://downloads.lede-project.org/snapshots/packages/mipsel_24kc/packages/sqm-scripts_1.0.9-1_all.ipk.
#Installing tc (4.4.0-5) to root...
#Downloading http://downloads.lede-project.org/snapshots/packages/mipsel_24kc/base/tc_4.4.0-5_mipsel_24kc.ipk.
#Installing kmod-sched-core (4.4.32-1) to root...
#Downloading http://downloads.lede-project.org/snapshots/targets/ramips/mt7621/packages/kmod-sched-core_4.4.32-1_mipsel_24kc.ipk.
#Installing kmod-sched (4.4.32-1) to root...
#Downloading http://downloads.lede-project.org/snapshots/targets/ramips/mt7621/packages/kmod-sched_4.4.32-1_mipsel_24kc.ipk.
#Installing kmod-ifb (4.4.32-1) to root...
#Downloading http://downloads.lede-project.org/snapshots/targets/ramips/mt7621/packages/kmod-ifb_4.4.32-1_mipsel_24kc.ipk.
#Configuring kmod-sched-core.
#Configuring tc.
#Configuring kmod-sched.
#Configuring kmod-ifb.
#Configuring sqm-scripts.

System
Hostname	lede
Model	ZBT-WG3526
Firmware Version	LEDE Reboot r0+2292 / LuCI Master (git-16.324.51057-1c27f6b) from 22.11.2016
Kernel Version	4.4.32
lede-ramips-mt7621-zbt-wg3526-squashfs-sysupgra..> 22-Nov-2016 12:56             3932323

 

More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=303