Bugs in new kernels

[Timothy Murphy]

John Wendel wrote:

>> Actually, I don't understand why people find the Fedora kernels
>> so attractive.
>> They are rarely any improvement on the standard kernels
>> from http://www.kernel.org .

> I've posted about this before, without any replies, so here I go again ...
> 
> I have been unable to get a kernel.org kernel to run correctly on FC4.
> The same kernel configuration works fine on FC3. The last kernel I tried
> was 2.6.12.5.
> 
> I'd appreciate any tips you might have for getting a stock kernel running.

I don't set up as a great expert on kernel compilation
(or any computing subject, for that matter).
But I guess you are asking me ...

First of all, I gather your compilation went OK,
but the compiled kernel does not run.

If that is so, the problem probably lies in initrd.
My procedure, in brief, is
        make oldconfig xconfig
        make
        make modules_install
        make install

The last step runs mkinitrd (under Fedora),
installs the initrd*.img in /boot ,
and adds an appropriate entry to /etc/grub.conf .

I think sometimes mkinitrd does not choose the right modules.
In that case you could run linux under another kernel
(assuming you have one that runs),
add the required module(s) to /etc/modprobe.conf
and then run mkinitrd yourself.

Alternatively, some modules -
such as ext2/ext3 and scsi if you have SCSI disks - 
are better included in the kernel, IMHO,
though I think in theory it should always be possible
to include them in the initrd.

Final remark: I always save all my old .config files,
and load the most recent one when I run "make xconfig".
This has become very simple with (fairly) recent kernels,
with the window that comes up when you "make xconfig"
being much easier to use than it used to be.

I always say "make oldconfig xconfig",
and just answer Yes to all the questions I am asked,
and then load my previous config file.
I'm not really sure if there is any merit
in saying this rather than just "make xconfig".
I think there were a couple of kernels some time ago
when there were problems if one did not do this.

I'd be interested to know if there is in fact
any point in still saying "make oldconfig xconfig"
(assuming one is going to load an old config anyway),
or if it is just a fetish?

Re the title "Bugs in new kernels"
I've compiled most new kernels for some time,
and haven't encountered anything I would describe as a bug.




-- 
Timothy Murphy  
e-mail (<80k only): tim /at/ birdsnest.maths.tcd.ie
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland