Complete hang on 9.0-RELEASE

[Arnaud Lacombe]

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

 - Arnaud

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