== Summary ==
On ppc64le, the kernel is currently compiled for 64k page size.
This change proposes using the more common 4k page size.
Some HPC workloads may be disadvantaged slightly. Workstation users
are likely to encounter fewer bugs.
Some things, like the AMD Radeon GPU drivers, firmware or related
code, appear to be completely non-functional on the 64k page size.
Insufficient upstream developers are testing such issues on this
== Owner ==
* Name: [[User:pocock|Daniel Pocock]]
* Email: daniel(a)pocock.pro
== Detailed Description ==
== Feedback ==
Discussed several times on devel,
discussed upstream in the Raptor forum]
== Benefit to Fedora ==
Better first impression for users of ppc64le workstations.
Users can focus on reporting ppc64le bugs without being sidetracked by
page size bugs.
== Scope ==
* Proposal owners: [[DanielPocock]]
* Other developers: please volunteer by adding your name here
* Release engineering: [https://pagure.io/releng/issue/9939
** wait for 5.12 kernel, verify that it includes the Btrfs patches for
arbitrary 4k / 64k sector size, independent of the page size
** create a kernel with 4k page size to run on the ppc64le build servers
** ensure the default kernel RPM in the distribution has 4k page size
** perform the mass rebuild running on the 4k page size
** create an installer ISO based on the revised kernel with 4k page size
* Policies and guidelines: no, as it is an arch-specific issues, most
other architectures already have a 4k page size
* Trademark approval: N/A (not needed for this Change)
* Alignment with Objectives: none of the current objectives relate to
== Upgrade/compatibility impact ==
If the user has already formatted their root filesystem with Btrfs and
a 64k sector size, they need to be using a Fedora kernel that supports
both 4k and 64k. This is anticipated in a future kernel release, 5.12
and will hopefully be ready for F34 or
== User Experience ==
New GPUs are more likely to just work on this non-x86 architecture, as
long as the latest firmware, mesa, llvm are also used.
Btrfs, the default filesystem, will use the sector size identical to
the running kernel's page size. As the 4k page size is more common,
this will ensure Btrfs filesystems created on ppc64le hosts can be
used on x86 and other hosts without hassle.
== Dependencies ==
All RPMs must be rebuilt on a server running the final page size (4k)
== Contingency Plan ==
* Contingency mechanism: Prepare a kernel with the original 64k
config, install it on the build server, rebuild all the packages for
* Contingency deadline: whenever the last time for a full rebuild or
kernel change is possible
* Blocks release? Yes, full rebuild of all packages must be completed
He / Him / His
Senior Program Manager, Fedora & CentOS Stream