diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2024-04-18 12:09:08 -0700 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2024-05-01 23:18:48 +0900 |
| commit | b0e28a4b5becea84ae6fca5cbd8a6b80a134e223 (patch) | |
| tree | 436194932eee40c5eced2d6019b6d28287ffaf7a /include/linux/trace_recursion.h | |
| parent | 0dc715295d4143d1659879f7f50ad4e9a6f6a99c (diff) | |
ftrace: make extra rcu_is_watching() validation check optional
Introduce CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING config option to
control whether ftrace low-level code performs additional
rcu_is_watching()-based validation logic in an attempt to catch noinstr
violations.
This check is expected to never be true and is mostly useful for
low-level validation of ftrace subsystem invariants. For most users it
should probably be kept disabled to eliminate unnecessary runtime
overhead.
This improves BPF multi-kretprobe (relying on ftrace and rethook
infrastructure) runtime throughput by 2%, according to BPF benchmarks ([0]).
[0] https://lore.kernel.org/bpf/CAEf4BzauQ2WKMjZdc9s0rBWa01BYbgwHN6aNDXQSHYia47pQ-w@mail.gmail.com/
Link: https://lore.kernel.org/all/20240418190909.704286-1-andrii@kernel.org/
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Diffstat (limited to 'include/linux/trace_recursion.h')
| -rw-r--r-- | include/linux/trace_recursion.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/trace_recursion.h b/include/linux/trace_recursion.h index d48cd92d2364..24ea8ac049b4 100644 --- a/include/linux/trace_recursion.h +++ b/include/linux/trace_recursion.h @@ -135,7 +135,7 @@ extern void ftrace_record_recursion(unsigned long ip, unsigned long parent_ip); # define do_ftrace_record_recursion(ip, pip) do { } while (0) #endif -#ifdef CONFIG_ARCH_WANTS_NO_INSTR +#ifdef CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING # define trace_warn_on_no_rcu(ip) \ ({ \ bool __ret = !rcu_is_watching(); \ |