This was already enabled in 2022 (7b2b827d34bce12ea8aec1e370c32654eb46fd70)
but disabled when bpf support was enabled for use within systemd 243
(01b1f8af0442d0938bf1e7337f62ba6571b2fb1e).
Looks as we can enable both now in 6.12, so let's do that.
This not a panic reaction to the xz situation, but certainly an
experiment initiated by that. Let’s have a look at compression speed,
decompression (startup) speed and compression size.
Several changes to configs and packages must be done:
- enable kernel support for zstd compression for itself
- enable kernel support for zstd compression for the initramfs
- adopt firmware names in CONFIG_EXTRA_FIRMWARE
- let the initramfs be compressed with zstd
- compress firmware files with zstd (before re-building the kernel)
For some details see gitea issue #2.
This was disabled by accident in 2024-05 when bumping to 6.9.x
in commit 0cb31139d5263f6d2e406c0f673a5b61b5d7abdd.
For the original commit enabling SLS as CONFIG_SLS(sic!)
see commit d50c76cba87953a8570f7ae2f4a2354dfe165d31.
- enable CONFIG_BPF_LSM=Y
- CONFIG_DEBUG_INFO_BTF=Y, which needs dev-util/pahole.
Let's add it to try that fancy new shit of 2019 / systemd 243 ;)
Seriously, let's try eBPF support in systemd units as Gentoo/Linux
gained access by USE flags recently. Unfortunately it leads to some
disabled hardending features (randstruct). Let’s live with it for now.
