[PATCH v5 15/21] ratelimit: Simplify common-case exit path

[Paul E. McKenney]

By making "ret" always be initialized, and moving the final call to
ratelimit_state_inc_miss() out from under the lock, we save a goto and
a couple lines of code.  This also saves a couple of lines of code from
the unconditional enable/disable slowpath.

Link: https://lore.kernel.org/all/fbe93a52-365e-47fe-93a4-44a44547d601@paulmck-laptop/
Link: https://lore.kernel.org/all/20250423115409.3425-1-spasswolf@xxxxxx/
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Cc: Mateusz Guzik <mjguzik@xxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: John Ogness <john.ogness@xxxxxxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
 lib/ratelimit.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/lib/ratelimit.c b/lib/ratelimit.c
index 6a5cb05413013..7c6e864306db2 100644
--- a/lib/ratelimit.c
+++ b/lib/ratelimit.c
@@ -33,7 +33,7 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func)
 	int interval = READ_ONCE(rs->interval);
 	int burst = READ_ONCE(rs->burst);
 	unsigned long flags;
-	int ret;
+	int ret = 0;
 
 	/*
 	 * Zero interval says never limit, otherwise, non-positive burst
@@ -51,8 +51,6 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func)
 
 		/* Force re-initialization once re-enabled. */
 		rs->flags &= ~RATELIMIT_INITIALIZED;
-		if (!ret)
-			ratelimit_state_inc_miss(rs);
 		goto unlock_ret;
 	}
 
@@ -110,19 +108,17 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func)
 
 		if (n_left > 0) {
 			n_left = atomic_dec_return(&rs->rs_n_left);
-			if (n_left >= 0) {
+			if (n_left >= 0)
 				ret = 1;
-				goto unlock_ret;
-			}
 		}
 	}
 
-	ratelimit_state_inc_miss(rs);
-	ret = 0;
-
 unlock_ret:
 	raw_spin_unlock_irqrestore(&rs->lock, flags);
 
+	if (!ret)
+		ratelimit_state_inc_miss(rs);
+
 	return ret;
 }
 EXPORT_SYMBOL(___ratelimit);
-- 
2.40.1