[LEDE-DEV] LEDE Trunk RCU stalls with sqm scripts enabled

[Outback Dingo]

seems as soon as i enable sqm qos scripts regardless of using fq_codel
or cake im hitting RCO
issues, reboots even... as soon as i disable it... all is stable....
its a ZBT-WG3526

Firmware Version LEDE Reboot r2152+8 / LuCI Master (git-16.313.75284-4343b2f)
Kernel Version 4.4.30


[  149.490000] INFO: rcu_sched detected stalls on CPUs/tasks:
[  149.490000]  3-...: (0 ticks this GP) idle=b7c/0/0 softirq=3733/3733 fqs=0
[  149.500000]  (detected by 1, t=6003 jiffies, g=1039, c=1038, q=10655)
[  149.500000] Task dump for CPU 3:
[  149.510000] swapper/3       R running      0     0      1 0x00100000
[  149.510000] Stack : 00000000 00005ac7 8e049880 7ffdecec 00000000
80418a90 8045a2a4 80410000
[  149.510000]    8041275c 00000001 00000001 80412680 80412724
80410000 00000000 800132e8
[  149.510000]    00000000 00000001 8fc64000 8fc65ec0 80410000
8005c870 1100fc03 00000003
[  149.510000]    00000000 80410000 8045a2a4 8005c868 80410000
8001ade0 1100fc03 00000000
[  149.510000]    00000004 804124a0 000000a0 8001ade8 fefffbdb
aefffbfb fff77fe7 dfffffef
[  149.510000]    ...
[  149.550000] Call Trace:
[  149.550000] [<8000bba8>] __schedule+0x574/0x758
[  149.560000] [<800132e8>] r4k_wait_irqoff+0x0/0x20
[  149.560000]
[  149.560000] rcu_sched kthread starved for 6009 jiffies! g1039 c1038
f0x0 s3 ->state=0x1
[ 1326.670000] INFO: rcu_sched detected stalls on CPUs/tasks:
[ 1326.670000]  2-...: (0 ticks this GP) idle=998/0/0
softirq=56566/56566 fqs=0
[ 1326.680000]  (detected by 1, t=6003 jiffies, g=14603, c=14602, q=9455)
[ 1326.680000] Task dump for CPU 2:
[ 1326.690000] swapper/2       R running      0     0      1 0x00100000
[ 1326.690000] Stack : 00000000 00000001 0000000a 00000000 00000000
00000001 8045a2a4 80410000
[ 1326.690000]    8041275c 00000001 00000000 804125e0 80412724
80410000 00000000 800132e8
[ 1326.690000]    1100fc03 00000002 8fc62000 8fc63ec0 80410000
8005c870 1100fc03 00000002
[ 1326.690000]    00000000 80410000 8045a2a4 8005c868 80410000
8001ade0 1100fc03 00000000
[ 1326.690000]    00000004 804124a0 000000a0 8001ade8 fbffbfdf
7fff7b3b 7ffaeff8 67fbffff
[ 1326.690000]    ...
[ 1326.730000] Call Trace:
[ 1326.730000] [<8000bba8>] __schedule+0x574/0x758
[ 1326.740000] [<800132e8>] r4k_wait_irqoff+0x0/0x20
[ 1326.740000]
[ 1326.740000] rcu_sched kthread starved for 6009 jiffies! g14603
c14602 f0x0 s3 ->state=0x1
[ 1392.200000] INFO: rcu_sched detected stalls on CPUs/tasks:
[ 1392.200000]  2-...: (0 ticks this GP) idle=c80/0/0
softirq=56566/56566 fqs=0
[ 1392.210000]  (detected by 3, t=6003 jiffies, g=14669, c=14668, q=11973)
[ 1392.210000] Task dump for CPU 2:
[ 1392.220000] swapper/2       R running      0     0      1 0x00100000
[ 1392.220000] Stack : 00000000 4e88ab25 00000148 ffffffff 0000011d
773206f0 8045a2a4 80410000
[ 1392.220000]    8041275c 00000001 00000000 804125e0 80412724
80410000 000010d9 800132e8
[ 1392.220000]    1100fc03 00000002 8fc62000 8fc63ec0 80410000
8005c870 1100fc03 00000002
[ 1392.220000]    00000000 80410000 8045a2a4 8005c868 80410000
8001ade0 1100fc03 00000000
[ 1392.220000]    00000004 804124a0 000000a0 8001ade8 fbffbfdf
7fff7b3b 7ffaeff8 67fbffff
[ 1392.220000]    ...
[ 1392.260000] Call Trace:
[ 1392.260000] [<8000bba8>] __schedule+0x574/0x758
[ 1392.270000] [<800132e8>] r4k_wait_irqoff+0x0/0x20
[ 1392.270000]
[ 1392.270000] rcu_sched kthread starved for 6009 jiffies! g14669
c14668 f0x0 s3 ->state=0x1