What every kernel programmer should know about Jump Labels

What every kernel programmer should know about Jump Labels

The article seems to include an enormous amount of extraneous detail, beyond what one might argue “every… programmer should know.”

Not being a kernel programmer, and not knowing much about this topic, I found these relatively terse (and, ostensibly, human-written) resources much more effective at explaining the topic:

• LWN: Jump label
• Kernel source (include/linux/jump_label.h): “Jump labels provide an interface…”
• Kernel documentation: Static keys

Having reviewed these, I skimmed the posted article for additional detail (e.g., nop⇋jmp encoding sizes,) and none of it was irrelevant, but most of it was extraneous and presented in a fashion that was nearly unreadably dense. Presumably, the motivation in §2† would have been better to provide at the beginning, the data structure listings in §7 would be better provided as just a code listing (or, better yet, a link to the code,) the preference for ASCII art is bewildering (it's worse than an HTML table or SVG diagramme, despite these ostensibly being just as easy to generate for the LLM,) and the verbiage (e.g., “two polarities: key default × branch hint”) quickly becomes exhausting, and the inclusion of a worked example in §13 is perplexing.

It's an interesting topic for someone interested in the Linux kernel or in low-level programming considerations, but I think the resources I shared above are actually far better, despite being… less text. My recommendation: read the above links; skip this guide.

† I know that my use of compose key makes me look like an LLM… but I felt obligated to keep the §s—a sequence I don't believe I have ever previously used—because I guessed the default sequence ought to be something like <Multi_key> <s> <o> <s>, and I guessed (mostly) right. Shall we not forget that computers, on occasion, should provide a measure of delight…?