ratelimit: Simplify common-case exit path

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@web.de/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>

diff --git a/lib/ratelimit.c b/lib/ratelimit.c
index 6a5cb0541301368868e1f987acc50f9e57434f43..7c6e864306db26822e706d1afd17a62109dcc838 100644 (file)
--- 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);