Kernel requires cmov feature - 12.04 LTS install hangs

[mörgæs]

I don't know of any hacks to get the new kernels to work, and in general I wouldn't spend long time on such a computer.

Lubuntu 10.04 will give you one year more. You could also try Puppy.

[martinr]

Thanks for your help.
I've got LUbuntu 10.04 up and running on the AMD K6-2 (although it feels slower that the bloody ******* XP, I'm flabbergasted by that?!).

If there are any plans of keeping a non CMOV Ubuntu strain alive, I'd be interested to hear about it.

Furthermore all information about what Ubuntu software is impacted by the lack of a complete set of CMOV instuctions in the processor is also very welcome (e.g. only impacts kernel vs impacts X11 directly, etc).

[mörgæs]

In the Buntu family there are no plans of supporting non-CMOV computers. You need to try other distros.

It surprises me that Lubuntu 10.04 is so slow. Does top show a heavy load?

[martinr]

In the Buntu family there are no plans of supporting non-CMOV computers. You need to try other distros.

It surprises me that Lubuntu 10.04 is so slow. Does top show a heavy load?

That's a shame, so the last of the Socket 7 CPU's outlived Ubuntu.

They don't build hardware like that any more.

Regarding loads, this is what I get:

top - 10:09:32 up 8 min,  2 users,  load average: 2.49, 1.71, 0.90
Tasks: 108 total,   1 running, 106 sleeping,   0 stopped,   1 zombie
Cpu(s): 17.9%us,  8.5%sy,  0.0%ni, 72.6%id,  0.0%wa,  0.7%hi,  0.3%si,  0.0%st
Mem:    250688k total,   242080k used,     8608k free,    11584k buffers
Swap:  2062328k total,        0k used,  2062328k free,   134960k cached

107 processes for LUbuntu, pretty much?!

[mörgæs]

107 processes for LUbuntu, pretty much?!

No, that's normal.

What matters most are the columns %CPU and %MEM just below the text you pasted (that is, below the white bar in top).

Anyway, this computer is allowed to be a little under strain. 256 MB memory and a 12 years old CPU...

[martinr]

I tested with XUbuntu 12.04 beta and I could have sworn that it worked!

I was able to retest the beta2 and it also runs into the same missing CMOV trouble. I was mistaken and probably tested the beta2 before the processor upgrade. Although the K6-2 is 3 times as fast as the Pentium, it's lacking a complete set of CMOV instructions.

[martinr]

Does somebody know what Ubuntu software is impacted by the lack of a complete set of CMOV instructions in the processor? (e.g. only impacts kernel vs impacts X11 directly, etc).

In the pre-installation manual of 12.04 I found the following:

However, Ubuntu precise will not run on i586 or earlier processors. Despite the architecture name "i386", support for actual 80386 processors (and their clones) was dropped with the Sarge (r3.1) release of Debian[2]. (No version of Linux has ever supported the 286 or earlier chips in the series.) Support for i586 and lower processors, as well as for i686 processors without the cmov instruction, was dropped in Ubuntu 10.10. Most i686 and later processors are still supported[3].

Where references 2 and 3 point to:

[2] We have long tried to avoid this, but in the end it was necessary due a unfortunate series of issues with the compiler and the kernel, starting with an bug in the C++ ABI provided by GCC. You should still be able to run Ubuntu on actual 80386 processors if you compile your own kernel and compile all packages from source, but that is beyond the scope of this manual.

[3] Many Ubuntu packages will actually run slightly faster on modern computers as a positive side effect of dropping support for these old chips. The i486, introduced in 1989, has three opcodes (bswap, cmpxchg, and xadd) which the i386, introduced in 1986, did not have. Previously, these could not be easily used by most Ubuntu packages; now they can.

This talks about dropping support for the i486, introduced in 1989 and not about the i686 (AMD K6-2) without a complete set of CMOV instructions.

Does somebody know what Ubuntu software is impacted by the lack of a complete set of CMOV instructions in the processor?

[martinr]

Lubuntu 10.04 will give you one year more.

After some tuning I've got Lubuntu running okay. During my last upgrade I read that the kerner is supported untin 2015.

What support will stop exactly in a year and what will it affect?

[mörgæs]

I don't know exactly which packages are running out of support, and regardless of the support question: As I mentioned before my advice is to consider switching to some (possibly used, but still) younger gear.

[martinr]

I don't know exactly which packages are running out of support, and regardless of the support question: As I mentioned before my advice is to consider switching to some (possibly used, but still) younger gear.

Your advise is noted, but the younger gear is too power hungry for my purposes. I invested a lot of time in optimizing it and would like to enjoy it for a while.