Proposed additions to release notes (was: Re: i686 ---> i586, i386 ---> i586, x86_64 stays the same)

Christopher Beland beland at alum.mit.edu
Tue Apr 14 18:35:46 UTC 2009


I'm planning to add the below to the F11 beta release notes under
"What's New" in a few days, but please let me know if there are any
objections, corrections, clarifications, etc.

-B.

===Package rebuild===

All .i386 and .i486 packages have been rebuilt as .i586 (Pentium class).
These designations represent the ''minimum'' supported architecture
version; Fedora 11 is ''optimized'' for Pentium 4-compatible and later
processors.  Fedora has never officially supported pre-Pentium
architectures, and dropping any remaining backwards compatibility with
these chips further improves performance and allows for code
simplification (for example in glibc).

===.i386/.i686 kernel changes===

As part of the package rebuild (described above), the kernel.i386 RPM is
no longer produced.  For different reasons, the kernel.i686 RPM is also
no longer built. The following kernel choices ''are'' available in
Fedora 11:

* kernel.i586, for those requiring compatibility with a Pentium-class
architecture or who do not have a PAE and NX capable processor.
* kernel-PAE.i686, which requires a PAE and NX capable processor with
Pentium PRO-class or later architecture.

These designations represent the ''minimum'' supported architecture
version; Fedora 11 is ''optimized'' for Pentium 4-compatible and later
processors.

After analyzing the differences between the i585 and i686 architectures,
dropping the non-PAE i686 kernel is not expected to have a negative
performance impact for those required to drop to the kernel.i586
package.  The kernel-PAE.i686 RPM supports security features like
ExecShield, and can address up to 64GB of RAM (up from 4GB for the
standard kernel).

Anaconda (the recommended install method) will automatically choose the
best kernel.

If you are using the "yum upgrade" method (not recommended), you may
receive the kernel.i586 package even if your processor would support the
kernel-PAE.i686 package. To determine this, run the command:

:grep 'flags.* pae' /proc/cpuinfo | grep -wq nx && echo 'kernel-PAE'

If you see "kernel-PAE" in the output, then your CPU is capable of using
this package, and you can manually "yum install kernel-PAE".






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