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Date:      Fri, 6 Jun 2003 10:00:14 -0400
From:      Mike Makonnen <mtm@identd.net>
To:        "Robin P. Blanchard" <Robin.Blanchard@gactr.uga.edu>
Cc:        current@freebsd.org
Subject:   How to ask for help on this list (was Re: Reproducible hard freeze on 5.1-CURRENT)
Message-ID:  <20030606140015.HCMG12592.out001.verizon.net@kokeb.ambesa.net>
In-Reply-To: <EE3D3FBAFFCAED448C21C398FDAD91AC237417@EBE1.gc.nat>
References:  <EE3D3FBAFFCAED448C21C398FDAD91AC237417@EBE1.gc.nat>

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On Fri, 6 Jun 2003 08:48:17 -0400
"Robin P. Blanchard" <Robin.Blanchard@gactr.uga.edu> wrote:

> Upon launching samba-2.2.8a (via ports) on the below system, the machine
> immediately hard freezes. I've included interesting portions of kernel
> config. Any suggestions how I can acquire more useful information ?
[snip] 
> #options                WITNESS
> #options                WITNESS_DDB
> #options                WITNESS_SKIPSPIN
> #options                INVARIANTS
> #options                INVARIANT_SUPPORT
> #options                DIAGNOSTIC
[snip] 
> 
> #options        SCHED_4BSD
> options         SCHED_ULE

This is not to pick on you in particular. There have been a lot of these
lately and I just picked this one to reply to.

None of this is new, these points have already been made elsewhere and
people on this list should be familiar with them. But I'll go ahead and 
point them out anyway.

If you experience a freeze, panic, or any other fatal problem please keep in
mind the following things:

1. There is a reason SCHED_ULE is labeled 'experimental'. It means that this is
    a new feature that needs some more testing and deguggin. Don't be
    surprised if it panics your system, eats your homework, or causes your hair
    to fall out.

    If you insist on using it, then please properly label your email with such
    information, and at the very least try to determine if _not_ using it makes
    your problems go away.

2. Before you report a problem enable all the debugging options in your kernel
    configuration file.  If you don't want to put up with the reduction in
    performance, then build two kernels from the same source: one without the
    debuging options and one with.  When you hit a problem, boot into the
    kernel with the debugging options and try to reproduce the problem.  Report
    any Lock Oreder Reversals (LORs) and other errors reported by the kernel.
    When you do report a problem like "my box freezes" it is essential that you
    at least have 'options DDB' in your kernel so you can attempt to enter the
    kernel debugger and get an idea of what's happening. If enabling the
    debugging options makes your problems go away, that is helpful information
    in and of itself, so report it.

3. There is an entry in The Handbook and the Articles that provide information
    on how to obtain debuging information from your kernel. Greg Lehey also has
    an article about that in the works (see archives). Please read these before
    you ask "How can I get more debugging information."

4. Some problems, are caused by faulty hardware. The ports tree has some
    applications you can use to check your hardware (memtest86, etc). If you
    see random panics and/or freezes it may be a good idea to use some
    of these programs to check your hardware. Believe it or not, hardware does
    fail, so don't discount this possibility.

5. You can greatly increase the chance that your problem gets resolved if you
    provide good quality debugging information, and actually do some of the
    diagnosing yourself.  Even a partial attempt at solving the problem is
    better than nothing.

6. Finally, please try to understand that this is a volunteer project. Few
    developers actually get paid to work on FreeBSD, and when they do
    it's usually for something specific that their employer needs. Most
    developers give up free time during the week to work on FreeBSD.
    So, it may not be possible to devote the time and energy you believe
    your problem deserves.


Cheers.
-- 
Mike Makonnen  | GPG-KEY: http://www.identd.net/~mtm/mtm.asc
mtm@identd.net | D228 1A6F C64E 120A A1C9  A3AA DAE1 E2AF DBCC 68B9
mtm@FreeBSD.Org| FreeBSD - The Power To Serve



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