Post Syndicated from daroc original https://lwn.net/Articles/977993/

The kernel has a lot of code paths that are normally disabled: debugging print
statements, tracepoints, etc. To support these efficiently, there
is a common mechanism called

static keys that provides a way to enable or disable a
code path at run time, with effectively no overhead for disabled
branches. BPF programs have not been able to take advantage of static keys so far,
because they aren’t compiled into the kernel.
Now, it looks like BPF may be getting support for a similar mechanism —
and the design could also provide one of the components needed to support

jump tables, another missing feature.
Anton Protopovov presented his plans to add static keys to BPF at the 2024
Linux Storage,
Filesystem, Memory Management, and BPF Summit.