Complete hang on 9.0-RELEASE

[Arnaud Lacombe]

Hi,

On Wed, Feb 29, 2012 at 12:59 PM, Arnaud Lacombe <lacombar at gmail.com> wrote:
> 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...
>
No luck. None of BREAK or ALT_BREAK are responding. I will not touch
the system in the next few hours if you want me to test something on
it. In the event of 8.2-RELEASE or 9.0-RELEASE are  not meant to work
reliably on top of a 7.4-RELEASE userland, I will re-setup the test to
occurs on a clean 9.0-RELEASE system and re-try.

 - Arnaud