Take into account CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING when validating that RCU is watching when trying to setup rethooko on a function entry. This further (in addition to improvements in the previous patch) improves BPF multi-kretprobe (which rely on rethook) runtime throughput by 2.3%, according to BPF benchmarks ([0]). [0] https://lore.kernel.org/bpf/CAEf4BzauQ2WKMjZdc9s0rBWa01BYbgwHN6aNDXQSHYia47pQ-w@xxxxxxxxxxxxxx/ Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> --- kernel/trace/rethook.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c index fa03094e9e69..15b8aa4048d9 100644 --- a/kernel/trace/rethook.c +++ b/kernel/trace/rethook.c @@ -166,6 +166,7 @@ struct rethook_node *rethook_try_get(struct rethook *rh) if (unlikely(!handler)) return NULL; +#ifdef CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING /* * This expects the caller will set up a rethook on a function entry. * When the function returns, the rethook will eventually be reclaimed @@ -174,6 +175,7 @@ struct rethook_node *rethook_try_get(struct rethook *rh) */ if (unlikely(!rcu_is_watching())) return NULL; +#endif return (struct rethook_node *)objpool_pop(&rh->pool); } -- 2.43.0
