Shinigami

Shinigami is the Linux kernel fork that powers Kira, based on a longterm upstream release and patched for developer workloads on x86-64.

Versioning

Shinigami releases follow a two-part scheme:

6.12.85-shinigami-26.07

• LINUX_VERSION, the upstream Linux version this release is based on.
• SHINIGAMI_VERSION, the Kira patchset version, using the same YY.MM scheme as flux and kira-base.

The two axes are independent. Pulling a new upstream kernel bumps LINUX_VERSION only. Applying new Kira patches bumps SHINIGAMI_VERSION only. Both can change together when a release warrants it.

What's different from upstream

• BORE scheduler, for better interactive responsiveness under mixed workloads, tuned for a desktop and development machine rather than a server under constant load.
• Clang ThinLTO build, compiled with clang rather than gcc.
• A stripped configuration, with legacy drivers, old SCSI stacks, and unused subsystems removed to keep the kernel binary small and fast to build.

Patches are organized by category and every one has a documented reason, minimal diff from upstream is the goal:

Category	Purpose
perf/	Performance patches, including the BORE scheduler
mem/	Memory tuning
sec/	Security hardening
compat/	Hardware compatibility fixes
config/	Configuration-only changes

Inspecting the running kernel

Shinigami is built with CONFIG_IKCONFIG enabled, so the exact configuration of the kernel you are running is always available:

zcat /proc/config.gz

No need to trust a changelog, the running configuration is right there.

Updating

flux kernel-update

Downloads and verifies the latest signed Shinigami kernel, extracts it, and regenerates the GRUB configuration. Like any kernel update, this takes effect on the next reboot. See Updating Kira for the full picture.

Where to go next

• System Overview, for how the kernel fits into the rest of Kira.
• Updating Kira, for keeping the kernel and the rest of the system current.