> On 09-May-2019, at 4:53 AM, Roman Gushchin <g...@fb.com> wrote:
>
> On Wed, May 08, 2019 at 03:06:30PM +0530, Sachin Sant wrote:
>> While running LTP tests(specifically ptrace01) following WARNING is observed
>> on POWER8 LPAR running next-20190507 built using 4K page size.
>>
>> [ 3969.979492] msgrcv04 (433) used greatest stack depth: 9328 bytes left
>> [ 3981.452911] madvise06 (515): drop_caches: 3
>> [ 4004.575752] WARNING: CPU: 5 PID: 721 at kernel/cgroup/cgroup.c:6008
>> cgroup_exit+0x2ac/0x2c0
>> [ 4004.575781] Modules linked in: overlay rpadlpar_io rpaphp iptable_mangle
>> xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv4
>> ipt_REJECT nf_reject_ipv4 xt_tcpudp tun bridge stp llc kvm iptable_filter
>> pseries_rng rng_core vmx_crypto ip_tables x_tables autofs4 [last unloaded:
>> dummy_del_mod]
>> [ 4004.575837] CPU: 5 PID: 721 Comm: ptrace01 Tainted: G O
>> 5.1.0-next-20190507-autotest #1
>> [ 4004.575846] NIP: c000000001b3026c LR: c000000001b30054 CTR:
>> c000000001c9f020
>> [ 4004.575855] REGS: c000000171fff840 TRAP: 0700 Tainted: G O
>> (5.1.0-next-20190507-autotest)
>> [ 4004.575863] MSR: 800000010282b033
>> <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 44004824 XER: 20000000
>> [ 4004.575885] CFAR: c000000001b30078 IRQMASK: 1
>> [ 4004.575885] GPR00: c000000001b30054 c000000171fffad0 c000000003938700
>> c00000027b02fa18
>> [ 4004.575885] GPR04: c00000027b02fa00 0000000000000000 c000000003ae8700
>> 00000000001c180a
>> [ 4004.575885] GPR08: 0000000000000001 0000000000000001 c000000003ae8700
>> 0000000000000001
>> [ 4004.575885] GPR12: 0000000000004400 c00000001ec7ea80 c000000003a4d670
>> 0000000000000009
>> [ 4004.575885] GPR16: 0000000000000000 0000000000040100 00000000418004fc
>> 0000000008430000
>> [ 4004.575885] GPR20: 0000000000000009 0000000000000001 c0000001715e9200
>> c00000016d8f4d00
>> [ 4004.575885] GPR24: c000000171fffd90 0000000000000100 c000000168692478
>> c000000171fffb98
>> [ 4004.575885] GPR28: c000000168692400 c00000016d8f4d00 c0000000036420d0
>> c00000027b02fa00
>> [ 4004.575958] NIP [c000000001b3026c] cgroup_exit+0x2ac/0x2c0
>> [ 4004.575966] LR [c000000001b30054] cgroup_exit+0x94/0x2c0
>> [ 4004.575972] Call Trace:
>> [ 4004.575979] [c000000171fffad0] [c000000001b30054] cgroup_exit+0x94/0x2c0
>> (unreliable)
>> [ 4004.575990] [c000000171fffb30] [c0000000019cea98] do_exit+0x878/0x1ae0
>> [ 4004.575999] [c000000171fffc00] [c0000000019cfe4c] do_group_exit+0xac/0x1d0
>> [ 4004.576009] [c000000171fffc40] [c0000000019ed00c] get_signal+0x2bc/0x11c0
>> [ 4004.576019] [c000000171fffd30] [c000000001867b14]
>> do_notify_resume+0x384/0x900
>> [ 4004.576029] [c000000171fffe20] [c00000000183e844]
>> ret_from_except_lite+0x70/0x74
>> [ 4004.576037] Instruction dump:
>> [ 4004.576043] 314a0001 7d40492d 40c2fff4 3d42001b e92a7288 39290001
>> f92a7288 4bfffe5c
>> [ 4004.576056] 3d42001b e92a7258 39290001 f92a7258 <0fe00000> 4bfffe0c
>> 4be91e45 60000000
>> [ 4004.576071] ---[ end trace 82a1a7c19005ebd6 ]—
>>
>> The WARN_ONCE was added by following commit
>> 96b9c592def5 ("cgroup: get rid of cgroup_freezer_frozen_exit()”).
>>
>> Reverting the patch helps avoid the warning.
>
> Hi Sachin!
>
> Thank you for the report!
>
> Can you, please, check that the patch at https://lkml.org/lkml/2019/5/8/938
> <https://lkml.org/lkml/2019/5/8/938>
> solves the problem?
>
This patch fixes the problem for me.
Thanks
-Sachin
