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Kernel Summit 2007 - an advance view

Kernel Summit 2007 - an advance view

Posted Aug 30, 2007 10:53 UTC (Thu) by intgr (subscriber, #39733)
In reply to: Kernel Summit 2007 - an advance view by pointwood
Parent article: Kernel Summit 2007 - an advance view

There indeed appears to be no documentation on kernel testing for
non-developers; Linus is always asking for more testers of release
candidates, but it is often not straightforward without guidance on getting
the kernel installed and reporting problems.

Publishing LiveCDs for every release candidate would really be a waste,
and I am not aware of any. If compiling it all manually is over your head,
don't bother -- debugging and reporting problems also requires quite a bit
of technical know-how which you are unlikely to be prepared for.

This is the "short" guide to testing kernels: follow Linus's release
candidates; kerneltrap.org often reports -rc1 releases earlier than LWN
because it's not bound by the weekly schedule, but LWN is more consistent
-- the latest kernel release candidate is always reported on the kernel
page.

Preferably you would use git because it allows regressions to be bisected
to the patch that caused the regression:
http://www.kernel.org/pub/software/scm/git/docs/v1.4.4.4/...

If that's too complicated for you, get tarballs from www.kernel.org; build
the kernel (look for a howto/tutorial for your distro and take your time,
configuration might take a while for the first time); use it for everything
you normally use your computer for. When problems occur, write to LKML
(linux-kernel@vger.kernel.org) with the details of your hardware, your
configuration, any suspicious messages in dmesg, and what could have
caused the problem. Be sure to mention that it's a regression, and the
last kernel version that worked. More details at:
http://www.kernel.org/pub/linux/docs/lkml/reporting-bugs....
If you can be bothered, use the git-bisect feature to track down the
erroneous commit (see the link about git above).

Even if the kernel runs fine, keep your eye on dmesg for OOPSes -- these
are definitely bugs regardless of whether they cause you problems.

If there is no release candidate, you can try running the -mm kernel tree;
it contains experimental patches, many of which are probably going to be
merged into the mainline sooner or later. Be aware though, that it is more
likely to have serious bugs.


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Kernel Summit 2007 - an advance view

Posted Aug 30, 2007 18:57 UTC (Thu) by aegl (subscriber, #37581) [Link]

"Even if the kernel runs fine, keep your eye on dmesg for OOPSes -- these
are definitely bugs regardless of whether they cause you problems."

If you are regularly testing development kernels, it is really useful to save the dmesg(1) output from every kernel that you boot. I added this to my /etc/rc.local

REL=`uname -r`
TSTAMP=`date +%Y%m%d%H%M%S`
dmesg -s 100000 > /dmesg/$TSTAMP-$REL

Then when I notice something odd happening I can check whether anything new and interesting showed up in the boot messages.

I've spotted a lot of issues by simply running diff(1) on the current and previous dmesg output.

Kernel Summit 2007 - an advance view

Posted Sep 1, 2007 14:12 UTC (Sat) by kreutzm (subscriber, #4700) [Link]

Or use a tool to scan your log files (like logcheck). When I try out a new kernel, I immediately get all new lines which I can then add to the log check rules after I acknowledged them (and possibly took other action).

Kernel Summit 2007 - an advance view

Posted Aug 31, 2007 1:41 UTC (Fri) by rddunlap (subscriber, #27065) [Link]

Have you seen the "Linux Kernel Tester's Guide" ?

http://www.stardust.webpages.pl/files/handbook/handbook-e...
or just
http://www.stardust.webpages.pl/files/handbook/handbook-e... for
the non-rc1 version.

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