[$] A plan to make BPF kfuncs polymorphic

David Vernet kicked off the BPF track at 2024's BPF track at theLinux Storage,Filesystem, Memory Management, and BPF Summitwith atalk about polymorphic kfuncs - or, with less jargon, kernel functions that canbe called from BPF which use different implementations depending on context.He explained how this would be useful tothe sched_ext BPF scheduling framework,but expected it to be helpful inother areas as well.