[linux-elitists] netconsole module - kernel dmesg-over-network logging

Karsten M. Self karsten@linuxmafia.com
Fri Dec 12 11:23:24 PST 2008


on Fri, Dec 12, 2008 at 09:07:34AM -0800, Don Marti (dmarti@zgp.org) wrote:
> begin Greg KH quotation of Thu, Dec 11, 2008 at 07:54:38PM -0800:
> > On Thu, Dec 11, 2008 at 05:13:49PM -0800, Don Marti wrote:
> > > begin Karsten M. Self quotation of Thu, Dec 11, 2008 at 02:38:22PM -0800:
> > > 
> > > > For testing, you want to generate some kernel activity.
> > > ....
> > > > I'm open to other suggestions.
> > > 
> > > A module that just does a printk and then refuses
> > > to be inserted?  Insmod it every time you want a
> > > test line.
> > 
> > Heh, Alt-sysrq-T is much nicer than having to insert kernel code.  Or
> > one of the other sysrq keys if you just want the kernel to output a line
> > of text.
> 
> Yes, but with the module you can make it say whatever
> you want.
> 
> Just looking at Documentation/sysrq.txt you
> can do sysrq remotely too, without having to be at the
> keyboard.  This does a sync and logs two lines:
>   echo "echo s > /proc/sysrq-trigger" | sudo sh

*Awesome*.  Now _that_ is the reason I post stuff like this to list --
to flesh out the start of a good idea.  Thanks, Don.

Having also just revisited the sysrq docs, I note a few features I don't
recall from earlier times, including:

  - 'w' Dump tasks that are in uninterruptable (blocked) state
  - 'f' Calls oom_kill to kill a memory hog process

... and a few others which may have existed before but I didn't note,
such as 'd' (show locks), 'n' (make RT tasks niceable), and some
hardware-specific tools (v, x, g).

Fun & joy (really!).


Peace

-- 
Karsten M. Self <karsten@linuxmafia.com>        http://linuxmafia.com/~karsten
    Ceterum censeo, Caldera delenda est.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 191 bytes
Desc: Digital signature
Url : http://allium.zgp.org/pipermail/linux-elitists/attachments/20081212/32489bdc/attachment.pgp 


More information about the linux-elitists mailing list