Post-mortem crash analysis on SNB laptop?

Post-mortem crash analysis on SNB laptop?

[Dan McCabe]

My SNB laptop completely locks up every now and then (maybe twice a 
day). Is there any good way to look at post-mortem data to help my 
diagnose this issue.

I've seen discussions suggesting that I ssh into the machine, but I 
can't even do that.

TIA

cheers, danm

Re: Post-mortem crash analysis on SNB laptop?

[Chris Wilson]

On Wed, 22 Jun 2011 10:35:24 -0700, Dan McCabe <zen3d.linux@gmail.com> wrote:
> My SNB laptop completely locks up every now and then (maybe twice a 
> day). Is there any good way to look at post-mortem data to help my 
> diagnose this issue.
> 
> I've seen discussions suggesting that I ssh into the machine, but I 
> can't even do that.

The best that I found is to run netconsole and listen for any random oops.
Having been bitten by hard hangs with early SNB chips, my systems all have
i915.reset=0 which helped at that time, and may still help if the hard
hang is due to us doing something stupid whilst trying to reset the chip.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre

Re: Post-mortem crash analysis on SNB laptop?

[Ben Widawsky]

On Wed, Jun 22, 2011 at 10:35:24AM -0700, Dan McCabe wrote:
> My SNB laptop completely locks up every now and then (maybe twice a 
> day). Is there any good way to look at post-mortem data to help my 
> diagnose this issue.
> 
> I've seen discussions suggesting that I ssh into the machine, but I 
> can't even do that.
> 
> TIA
> 
> cheers, danm

Netconsole is nice for capturing the last dying breaths (with the
appropriate drm.debug flags, I usually use 0x6, but I guess 0xe is the
safest).

Assuming netconsole is built as a module, you can run something like
this on the crashing machine:
modprobe netconsole netconsole=6665@${IP_ADDRESS}/eth0,6666@${REMOTE_IP}/${REMOTE_MAC}

And this on some remote machine:
netcat -u -l -p 6666

Re: Post-mortem crash analysis on SNB laptop?

[Chris Wilson]

On Wed, 22 Jun 2011 10:50:41 -0700, Ben Widawsky <ben@bwidawsk.net> wrote:
> And this on some remote machine:
> netcat -u -l -p 6666

One issue that I found with netcat (at least in the incarnation above) is
that it fails to listen for more than one connection (even on UDP). Am I
doing it wrong? I ended up using a very simple UDP reader instead.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre

Re: Post-mortem crash analysis on SNB laptop?

[Ben Widawsky]

On Wed, Jun 22, 2011 at 07:08:41PM +0100, Chris Wilson wrote:
> On Wed, 22 Jun 2011 10:50:41 -0700, Ben Widawsky <ben@bwidawsk.net> wrote:
> > And this on some remote machine:
> > netcat -u -l -p 6666
> 
> One issue that I found with netcat (at least in the incarnation above) is
> that it fails to listen for more than one connection (even on UDP). Am I
> doing it wrong? I ended up using a very simple UDP reader instead.
> -Chris

I normally use different ports for different machines to avoid this. I
actually have a script which I run that does the correct stuff based on
the hostname.

> 
> -- 
> Chris Wilson, Intel Open Source Technology Centre