scx: Make kconfig symbols weak #2695
Conversation
See the docs for __kconfig[1], on some systems if __weak is not used it can cause libbpf to error out on loading. [1] https://docs.ebpf.io/ebpf-library/libbpf/ebpf/__kconfig/ Signed-off-by: Daniel Hodges <[email protected]>
There was a problem hiding this comment.
This prevents the libbpf error, but then we may fail to read the right .config values.
Some schedulers for example use CONFIG_HZ, that is evaluated as 0 if __kconfig is not resolved.
So this change looks ok, but we should also change the schedulers to handle this specific use case (CONFIG_HZ == 0), either by setting a fallback value or exiting with a specific error message like "kernel .config not found try installing kernel-headers" or something similar.
Same with other .config values, like CONFIG_NR_CPUS.
|
@hodgesds -- I would be a bit out of context. In the first place, why is the kconfig not properly defined? That seems problematic already. |
On bazzite and some fedora variants they don't ship with kernel configs built in or installed so libbpf fails. Going to resolve this with #2704 as it seems like a better solution. |
See the docs for __kconfig[1], on some systems if __weak is not used it can cause libbpf to error out on loading.
[1] https://docs.ebpf.io/ebpf-library/libbpf/ebpf/__kconfig/