Re: [lkp] [net] 9317bb6982: INFO: task cat-kmsg:893 blocked for more than 300 seconds.

[Eric Dumazet]

On Mon, May 9, 2016 at 6:26 PM, Huang, Ying <ying.huang@xxxxxxxxxxxxxxx> wrote:
> Hi, Eric,
>
> kernel test robot <ying.huang@xxxxxxxxxxxxxxx> writes:
>> FYI, we noticed the following commit:
>>
>> git://internal_merge_and_test_tree devel-catchup-201604281529
>> commit 9317bb69824ec8d078b0b786b6971aedb0af3d4f ("net: SOCKWQ_ASYNC_NOSPACE optimizations")
>>
>> on test machine: vm-kbuild-2G: 2 threads qemu-system-x86_64 -enable-kvm -cpu Haswell,+smep,+smap with 2G memory
>>
>> caused below changes:
>>
>>
>> +--------------------------------------------------+------------+------------+
>> |                                                  | 210732d16d | 9317bb6982 |
>> +--------------------------------------------------+------------+------------+
>> | boot_successes                                   | 40         | 13         |
>> | boot_failures                                    | 0          | 27         |
>> | INFO:task_blocked_for_more_than#seconds          | 0          | 27         |
>> | RIP:native_safe_halt                             | 0          | 20         |
>> | RIP:native_write_msr_safe                        | 0          | 27         |
>> | Kernel_panic-not_syncing:hung_task:blocked_tasks | 0          | 27         |
>> | backtrace:__close_fd                             | 0          | 27         |
>> | backtrace:SyS_close                              | 0          | 27         |
>> | backtrace:cpu_startup_entry                      | 0          | 19         |
>> | backtrace:watchdog                               | 0          | 27         |
>> | RIP:__lock_acquire                               | 0          | 2          |
>> | backtrace:rpc_async_schedule                     | 0          | 2          |
>> | backtrace:lock_acquire                           | 0          | 1          |
>> | RIP:delay_tsc                                    | 0          | 1          |
>> | backtrace:SYSC_epoll_wait                        | 0          | 1          |
>> | backtrace:SyS_epoll_wait                         | 0          | 1          |
>> | RIP:pvclock_clocksource_read                     | 0          | 1          |
>> | RIP:xs_reclassify_socket                         | 0          | 1          |
>> | backtrace:xs_tcp_setup_socket                    | 0          | 2          |
>> | RIP:insert_work                                  | 0          | 1          |
>> +--------------------------------------------------+------------+------------+
>
> We recently found this patch cause NFS hang in 0day/LKP test system.
> The NFS export can be mounted, but after a while all read/write to NFS
> mount blocked.  This influenced the 0day/LKP testing.  Could you help us
> to fix this?
>
> Best Regards,
> Huang, Ying


I need to officially submit this patch :
http://www.spinics.net/lists/netdev/msg375777.html

Thanks.