Dropping i386 non-PAE as a supported kernel flavour in Precise Pangolin

[Steven]

I hate to revive this, but I just wanted to share that the 1.4GHz Pentium M
in my Dell Latitude D505 from 2004 does not support the PAE kernel in
Precise. Found that out just now when testing a Lubuntu Precise daily
livecd for the first time.

Just thought everyone should know that non-pae doesn't mean 16 years ago --
it means 8 years ago, at least for me, on a perfectly good 512MB RAM system
that I use as my main production machine.

-Stenten


On Mon, Nov 28, 2011 at 4:48 PM, Tim Gardner <tim.gardner at canonical.com>wrote:

> On 11/28/2011 11:44 AM, Kees Cook wrote:
>
>> On Mon, Nov 28, 2011 at 09:40:53AM -0700, Tim Gardner wrote:
>>
>>> non-pae has a ginormous and ugly NX emulation patch
>>>
>>
>> This is about dropping non-PAE support, not dropping non-NX support. The
>> NX
>> emulation patch must remain in the kernel since a large number of systems
>> have PAE but not NX.
>>
>> You can see this in the table here:
>> https://wiki.ubuntu.com/**Security/Features#nx<https://wiki.ubuntu.com/Security/Features#nx>
>> Dropping non-PAE just eliminates the top line in that table. NX-emu will
>> still be needed.
>>
>>
> I guess you are correct. I naively assumed that execute-disable was
> introduced with PAE in the Pentium Pro series. However, it did not appear
> in Intel CPUs until Pentium 4 (approx Q1 2005). AMD had it from the
> beginning in the Athlon series.
>
>
>  that has consumed substantial maintenance resources in the past,
>>>
>>
>> I'm also curious about this claim, as you've expressed to me in the past
>> that carrying it has been surprisingly trivial. In fact, since I'm the one
>> maintaining it these days, it's actually going to require 0 resources from
>> Canonical. ;)
>>
>> http://git.kernel.org/?p=**linux/kernel/git/kees/linux.**
>> git;a=shortlog;h=refs/heads/**nx-emu<http://git.kernel.org/?p=linux/kernel/git/kees/linux.git;a=shortlog;h=refs/heads/nx-emu>
>>
>>
> I did say "in the past". I remember encountering several issues with the
> early implementation, as well as maintenance hassles while 32 and 64 bit
> arch support was converging. I would characterize the NX emulation patch as
> deeply intrusive, arguably one of the more complex patches against the core
> of Linux that we carry.
>
> Its a moot point given the model gap between PAE and NX introduction.
>
>
>  The kernel team has limited resources. Obviously I want to apply
>>> what resources we have to the problems that affect the most
>>> important platforms. Furthermore, I anticipate new ARM flavours in
>>> the coming months which will take up any slack afforded by the loss
>>> of non-PAE.
>>>
>>
>> I'm curious why pushing non-PAE to universe and leaving it in the main
>> linux source package is a burden? Then people using non-PAE get automatic
>> security updates without any hassle on anyone's part. This is what the
>> Ubuntu Security Team manager wants:
>> https://lists.ubuntu.com/**archives/ubuntu-devel/2011-**
>> November/034457.html<https://lists.ubuntu.com/archives/ubuntu-devel/2011-November/034457.html>
>> as well as the Ubuntu Platform Team manager wants:
>> https://lists.ubuntu.com/**archives/ubuntu-devel/2011-**
>> November/034463.html<https://lists.ubuntu.com/archives/ubuntu-devel/2011-November/034463.html>
>>
>> I'm not convinced there's enough evidence to say that dropping it from the
>> main linux source package will actually save any time at all.
>>
>>
> Dropping this flavour saves 5 minutes per build on a 4-way 80 thread
> server, which for some of the team can add up to quite a bit of time over
> the course of a day. Its one less variant that needs to be tested in Q/A,
> and its one less flavour we have to mess with in our meta and LBM packages.
>
>
> rtg
> --
> Tim Gardner tim.gardner at canonical.com
>
> --
> kernel-team mailing list
> kernel-team at lists.ubuntu.com
> https://lists.ubuntu.com/**mailman/listinfo/kernel-team<https://lists.ubuntu.com/mailman/listinfo/kernel-team>
>
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