Complete hang on 9.0-RELEASE

[Arnaud Lacombe]

Hi,

On Mon, Feb 27, 2012 at 12:48 PM, Arnaud Lacombe <lacombar at gmail.com> wrote:
> Hi,
>
> On Mon, Feb 27, 2012 at 10:36 AM, Attilio Rao <attilio at freebsd.org> wrote:
>> 2012/2/27, Arnaud Lacombe <lacombar at gmail.com>:
>>> Hi,
>>>
>>> On Tue, Feb 14, 2012 at 11:41 AM, Arnaud Lacombe <lacombar at gmail.com> wrote:
>>>> Hi folks,
>>>>
>>>> For the records, I was running some tests yesterday on top of a
>>>> 9.0-RELEASE, amd64, kernel when the box hanged. At the time of the
>>>> hang, the box was running a process with about 2800 threads with heavy
>>>> IPC between 1400 writers and 1400 readers. The box was in single user
>>>> mode (/bin/sh coming from FreeBSD 7.4-STABLE). Here is the beginning
>>>> of the dmesg:
>>>>
>>> This happened a second time, now with FreeBSD 8.2-RELEASE. Complete
>>> machine hang. The machine was running about 4000 threads in a single
>>> process, all the other condition are the same.
>>
>> Arnaud,
>> can you please break in your kernel via KDB, collect the following
>> informations from the DDB prompt:
>> - ps
>> - alltrace
>> - show allpcpu
>> - possibly get a coredump with 'call doadump'
>>
> Will do, but I'll need to rebuild a kernel to include DDB.
>
>> and in the end provide all those along with kernel binary and possibly
>> sources somewhere?
>>
> I'll be testing a bare `release/8.2.0' with the following patch:
>
> diff --git a/sys/amd64/conf/GENERIC b/sys/amd64/conf/GENERIC
> index c3e0095..7bd997f 100644
> --- a/sys/amd64/conf/GENERIC
> +++ b/sys/amd64/conf/GENERIC
> @@ -79,6 +79,10 @@ options      INCLUDE_CONFIG_FILE     # Include this
> file in kernel
>
>  options        KDB           # Kernel debugger related code
>  options        KDB_TRACE     # Print a stack trace for a panic
> +options        DDB
> +options        BREAK_TO_DEBUGGER
> +options        ALT_BREAK_TO_DEBUGGER
>
>  # Make an SMP-capable kernel by default
>  options        SMP           # Symmetric MultiProcessor Kernel
>
ok, it happened again after 2 days, the process was running about 3200
threads. I'm trying to break into DDB and let you know, I'm not that
successful for now...

 - Arnaud

>  - Arnaud
>
>> Thanks,
>> Attilio
>>
>>
>> --
>> Peace can only be achieved by understanding - A. Einstein