Subject: Re: [next-20170609] Oops while running CPU off-on (cpuset.c/cpuset_can_attach)

From: Tejun Heo <[email-masked]>
Date: Tue, 27 Jun 2017 11:36:08 -0400

Hello, Abdul.

Sorry about the long delay.

On Mon, Jun 12, 2017 at 04:53:42PM +0530, Abdul Haleem wrote:
> linux-next kernel crashed while running CPU offline and online.
> 
> Machine: Power 8 LPAR
> Kernel : 4.12.0-rc4-next-20170609
> gcc : version 5.2.1
> config: attached
> testcase: CPU off/on
> 
> for i in $(seq 100);do 
>     for j in $(seq 0 15);do 
>         echo 0 >  /sys/devices/system/cpu/cpu$j/online
>         sleep 5
>         echo 1 > /sys/devices/system/cpu/cpu$j/online
>     done
> done
> 
...
> NIP [c0000000001d6868] cpuset_can_attach+0x58/0x1b0

Can you please map this to the source line?

> LR [c0000000001d6858] cpuset_can_attach+0x48/0x1b0
> Call Trace:
> [c00000000c72b9a0] [c0000000001d6858] cpuset_can_attach+0x48/0x1b0
> (unreliable)
> [c00000000c72ba00] [c0000000001cbe80] cgroup_migrate_execute+0xb0/0x450
> [c00000000c72ba80] [c0000000001d3754] cgroup_transfer_tasks+0x1c4/0x360
> [c00000000c72bba0] [c0000000001d923c] cpuset_hotplug_workfn+0x86c/0xa20
> [c00000000c72bca0] [c00000000011aa44] process_one_work+0x1e4/0x580
> [c00000000c72bd30] [c00000000011ae78] worker_thread+0x98/0x5c0
> [c00000000c72bdc0] [c000000000124058] kthread+0x168/0x1b0
> [c00000000c72be30] [c00000000000b2e8] ret_from_kernel_thread+0x5c/0x74
> Instruction dump:
> f821ffa1 7c7d1b78 60000000 60000000 38810020 7fa3eb78 3f42ffed 4bff4c25 
> 60000000 3b5a0448 3d420020 eb610020 <e9230960> 7f43d378 e9290000
> f92af200 

Thanks.

-- 
tejun