On Thu, Mar 12, 2026 at 11:39:06AM -0400, Vineeth Remanan Pillai wrote:
On Thu, Mar 12, 2026 at 11:13 AM Steven Rostedt rostedt@goodmis.org wrote:
On Thu, 12 Mar 2026 11:04:56 -0400 "Vineeth Pillai (Google)" vineeth@bitbyteword.org wrote:
Add trace_invoke_##name() as a companion to trace_##name(). When a caller already guards a tracepoint with an explicit enabled check:
if (trace_foo_enabled() && cond) trace_foo(args);
trace_foo() internally repeats the static_branch_unlikely() test, which the compiler cannot fold since static branches are patched binary instructions. This results in two static-branch evaluations for every guarded call site.
trace_invoke_##name() calls __do_trace_##name() directly, skipping the redundant static-branch re-check. This avoids leaking the internal __do_trace_##name() symbol into call sites while still eliminating the double evaluation:
if (trace_foo_enabled() && cond) trace_invoke_foo(args); /* calls __do_trace_foo() directly */
Three locations are updated:
- __DECLARE_TRACE: invoke form omits static_branch_unlikely, retains the LOCKDEP RCU-watching assertion.
- __DECLARE_TRACE_SYSCALL: same, plus retains might_fault().
- !TRACEPOINTS_ENABLED stub: empty no-op so callers compile cleanly when tracepoints are compiled out.
Suggested-by: Steven Rostedt rostedt@goodmis.org Suggested-by: Peter Zijlstra peterz@infradead.org Signed-off-by: Vineeth Pillai (Google) vineeth@bitbyteword.org Assisted-by: Claude:claude-sonnet-4-6
I'm guessing Claude helped with the other patches. Did it really help with this one?
Claude wrote and build tested the whole series based on my guidance and prompt :-). I verified the series before sending it out, but claude did the initial work.
That seems like an unreasonable waste of energy. You could've had claude write a Coccinelle script for you and saved a ton of tokens.