Alexei Starovoitov [off-list ref] wrote:
- kprobes at the top of the function don't use traps and they've been
optimized over the years to have very low overhead
To quote kprobes.txt:
How Does a Kprobe Work?
-----------------------
When a kprobe is registered, Kprobes makes a copy of the probed
instruction and replaces the first byte(s) of the probed instruction
with a breakpoint instruction (e.g., int3 on i386 and x86_64).
Perhaps the docs need updating.
However, for my purposes, tracepoints are easier.
Anyway, as I said, I don't feel that strongly about the patch. It was useful
for me, and I thought it might be useful for other people.
David