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I took a good look at the current bits, and there are a few more things that need to be fixed before we can consider 'perf probe' for upstream. Firstly, this decoder bug is still not fixed: CHK include/linux/compile.h TEST posttest Error: ffffffff81068fe0: 66 0f 73 fd 04 pslldq $0x4,%xmm5 Error: objdump says 5 bytes, but insn_get_length() says 4 (attr:8000) make[1]: *** [posttest] Error 2 64-bit allyesconfig will trigger this for example, but the attached smaller config too. This needs to be fixed before we can apply any new commits. Secondly, the probe syntax is quite non-obvious currently. All the 'p' and -P gymnastics is just a barrier to the first-time user getting his first probe inserted successfully. The user need not worry about whether it's a 'kprobe' or a 'kretprobe'. The user should _specify_ what it wants to probe, and _that_ will lead to 'perf probe' picking the most suitable facility to achieve that kind of probing. It might be a kprobe, a kretprobe, or an mcount driven function probe, an existing tracepoint if it happens to be present in that place already - or some other future mechanism. The driving force must be a robust specification of 'what', not the mechanics of 'how'. Considering that, the current 'perf probe' syntax does not achieve that goal yet. Here are a few syntax suggestions The simpest probe syntax should be to add a probe to a single function name: perf probe +schedule _nothing else_. To remove it, the user should just do something like: perf probe -schedule (to be symmetric 'perf probe +schedule' should work as well) perf probe will make up a synthetic probe name for that - probe-1 for example. It will also pick the suitable probe mechanism (kprobes). All the other extensions and possibilities - arguments, variables, source code lines, etc. should be natural and intuitive extensions of this basic, minimal syntax. To insert a simple probe no -P should be needed, 'p', no ':' - no probe name even. Furthermore, there should be a way to list existing probes (and only probes), probably via 'perf list --probes' or 'perf probe --list'. Plus, 'perf probe --help' should list a few simple examples, beyond the syntax. Ok? Ingo
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