User:Pietinger/Experimental/Kernel Upgrade from 6.12 to 6.13

Kernel Upgrade from 6.12 to 6.13

Normally I do not recommend switching to a new major version of the kernel immediately, but to wait for two, three or four minor versions first. So I only looked at the new options, but haven't checked them yet. I also recommend that you only switch when the sys-kernel/linux-headers are also available in the kernel version (these usually take a little longer).

Notes for 6.13

A good overview of everything new in 6.13 can be found here:

The highlight of 6.13 is certainly the new lazy preemption model that provides more preemption opportunities than the voluntary preemption mode. This work greatly simplifies the kernel's preemption logic (and configuration options) while maintaining performance for throughput-oriented configurations. It is a significant change that should, eventually, reduce the amount of scheduling-related logic scattered through the non-scheduler parts of the kernel. It is said to be between "Desktop" (CONFIG_PREEMPT_VOLUNTARY) and "Low-Latency Desktop" (CONFIG_PREEMPT) in terms of latency and throughput. Read more about it in "The long road to lazy preemption": https://lwn.net/Articles/994322/ or watch Steven Rostedt in timestamp 29:39 - 37:44 on https://www.youtube.com/watch?v=AjFTVxAU3Vg (Explained in greater depth: https://www.youtube.com/watch?v=cVlT1CsRI18 )

Reiser-FS has now been finally removed.

Upgrade

I took over all but one default values with <return> when I did the make oldconfig. Here is a possible list (I have left out - as always - all new modules for some new hardware; if you have one of them, enable it):

1.
Preemption Model
  1. No Forced Preemption (Server) (PREEMPT_NONE)
> 2. Voluntary Kernel Preemption (Desktop) (PREEMPT_VOLUNTARY)
  3. Preemptible Kernel (Low-Latency Desktop) (PREEMPT)
  4. Scheduler controlled preemption model (PREEMPT_LAZY) (NEW)
choice[1-4?]: 4
2.
Split Lock Detect and Bus Lock Detect support (X86_BUS_LOCK_DETECT) [Y/n/?] (NEW)
3.
  Embedded Controller (ACPI_EC) [Y/n/?] (NEW)
4.
Legacy ARPTABLES support (IP_NF_ARPTABLES) [N/y/?] (NEW)
5.
  TLP Processing Hints (PCIE_TPH) [N/y/?] (NEW)
6.
  PCIe cooling support (PCIE_THERMAL) [N/y/?] (NEW)
7.
  AMD 3D V-Cache Performance Optimizer Driver (AMD_3D_VCACHE) [N/y/?] (NEW)
8.
Debug preemptible kernel (DEBUG_PREEMPT) [N/y/?] (NEW)

Remarks

1. I will definitely try it out and have selected it even if it is not (yet) the default. Please do not be surprised that the selection for the Real-Time kernel is now missing here; it now has its own menu item:

KERNEL Kernel

General setup  --->
    ...
    Preemption Model (Scheduler controlled preemption model)  --->
    [ ] Fully Preemptible Kernel (Real-Time)
    ...

2. Take the default.

3. I used the default even if my machine probably can't use it; but it is also standard in the default-config.

4. I do not use and have therefore adopted the default.

5. If I have understood correctly, this is currently only interesting for the latest AMD EPYC processors:

6. I have taken over the default.

7. Activate it only if you have an AMD processor with 3D V-cache technology.

8. Take the default.