Documentation Kernel Beat

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This section covers changes and important information regarding the {{Template:DocsDict/KernelVer}} based kernel in Fedora {{Template:DocsDict/BeatsVer}}.  The {{Template:DocsDict/KernelVer}} kernel includes:
 
This section covers changes and important information regarding the {{Template:DocsDict/KernelVer}} based kernel in Fedora {{Template:DocsDict/BeatsVer}}.  The {{Template:DocsDict/KernelVer}} kernel includes:
 
* Work on <code>paravirt_ops</code> in the upstream kernel has progressed sufficiently that the <code>kernel-xen</code> package has been obsoleted. For further details refer to [[Docs/Beats/Virtualization#Unified_Kernel_Image | Unified Kernel Image]].
 
 
  
 
=== Version ===
 
=== Version ===
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* The kernel-PAE, for use in 32-bit x86 systems with more than 4GB of RAM, or with CPUs that have a NX (No eXecute) feature.  This kernel support both uniprocessor and multi-processor systems.  Configured sources are available in the <code>kernel-PAE-devel</code> package.
 
* The kernel-PAE, for use in 32-bit x86 systems with more than 4GB of RAM, or with CPUs that have a NX (No eXecute) feature.  This kernel support both uniprocessor and multi-processor systems.  Configured sources are available in the <code>kernel-PAE-devel</code> package.
  
* Virtualization kernel for use with the Xen emulator package. Configured sources are available in the <code>kernel-xen-devel</code> package.
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* Debugging kernel, for use in debugging some kernel issues. Configured sources are available in the <code>kernel-debug-devel</code> package.
  
 
You may install kernel headers for all four kernel flavors at the same time. The files are installed in the <code>/usr/src/kernels/<version>[-PAE|-xen|-kdump] -<arch>/</code> tree. Use the following command:
 
You may install kernel headers for all four kernel flavors at the same time. The files are installed in the <code>/usr/src/kernels/<version>[-PAE|-xen|-kdump] -<arch>/</code> tree. Use the following command:
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{{Admon/note|x86 Kernel Includes Kdump|Both the x86_64 and the i686 kernels are relocatable, so they no longer require a separate kernel for kdump capability. PPC64 still requires a separate kdump kernel.}}
 
{{Admon/note|x86 Kernel Includes Kdump|Both the x86_64 and the i686 kernels are relocatable, so they no longer require a separate kernel for kdump capability. PPC64 still requires a separate kdump kernel.}}
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{{Admon/note|x86 Kernel Includes Paravirtualization|Both the x86_64 and the i686 kernels contain [[Docs/Beats/Virtualization#Unified_Kernel_Image | paravirt_ops]] support, so they no longer require a separate kernel for running under a Xen hypervisor.}}
  
 
{{Admon/note|Default Kernel Provides SMP|There is no separate SMP kernel available for Fedora on i386, x86_64, and ppc64.  Multiprocessor support is provided by the native kernel.}}
 
{{Admon/note|Default Kernel Provides SMP|There is no separate SMP kernel available for Fedora on i386, x86_64, and ppc64.  Multiprocessor support is provided by the native kernel.}}

Revision as of 20:47, 6 November 2008

Contents

Linux Kernel

Note.png
Deprecated or out of date content?
This content may be deprecated or out of date, it has not been updated since the Fedora 9 release notes.

This section covers changes and important information regarding the 2.6.27 based kernel in Fedora 21. The 2.6.27 kernel includes:

Version

Fedora may include additional patches to the kernel for improvements, bug fixes, or additional features. For this reason, the Fedora kernel may not be line-for-line equivalent to the so-called vanilla kernel from the kernel.org web site:

http://www.kernel.org/

To obtain a list of these patches, download the source RPM package and run the following command against it:

rpm -qpl kernel-<version>.src.rpm

Changelog

To retrieve a log of changes to the package, run the following command:

rpm -q --changelog kernel-<version>

If you need a user friendly version of the changelog, refer to http://wiki.kernelnewbies.org/LinuxChanges. A short and full diff of the kernel is available from http://kernel.org/git. The Fedora version kernel is based on the Linus tree.

Customizations made for the Fedora version are available from http://cvs.fedoraproject.org.

Kernel Flavors

Fedora 21 includes the following kernel builds:

  • Native kernel, for use in most systems. Configured sources are available in the kernel-devel package.
  • The kernel-PAE, for use in 32-bit x86 systems with more than 4GB of RAM, or with CPUs that have a NX (No eXecute) feature. This kernel support both uniprocessor and multi-processor systems. Configured sources are available in the kernel-PAE-devel package.
  • Debugging kernel, for use in debugging some kernel issues. Configured sources are available in the kernel-debug-devel package.

You may install kernel headers for all four kernel flavors at the same time. The files are installed in the /usr/src/kernels/<version>[-PAE|-xen|-kdump] -<arch>/ tree. Use the following command:

su -c 'yum install kernel{,-PAE,-xen,-kdump}-devel'

Select one or more of these flavors, separated by commas and no spaces, as appropriate. Enter the root password when prompted.

Note.png
x86 Kernel Includes Kdump
Both the x86_64 and the i686 kernels are relocatable, so they no longer require a separate kernel for kdump capability. PPC64 still requires a separate kdump kernel.
Note.png
x86 Kernel Includes Paravirtualization
Both the x86_64 and the i686 kernels contain paravirt_ops support, so they no longer require a separate kernel for running under a Xen hypervisor.
Note.png
Default Kernel Provides SMP
There is no separate SMP kernel available for Fedora on i386, x86_64, and ppc64. Multiprocessor support is provided by the native kernel.
Note.png
PowerPC Kernel Support
There is no support for Xen or kdump for the PowerPC architecture in Fedora. 32-bit PowerPC still has a separate SMP kernel.

Preparing for Kernel Development

Fedora 21 does not include the kernel-source package provided by older versions since only the kernel-devel package is required now to build external modules. Configured sources are available, as described above.

Important.png
Custom Kernel Building
For information on kernel development and working with custom kernels, refer to http://fedoraproject.org/wiki/Building_a_custom_kernel.

Reporting Bugs

Refer to http://kernel.org/pub/linux/docs/lkml/reporting-bugs.html for information on reporting bugs in the Linux kernel. You may also use http://bugzilla.redhat.com for reporting bugs that are specific to Fedora.