ratelimit: Use nolock_ret restructuring to collapse common case code

Now that unlock_ret releases the lock, then falls into nolock_ret, which
handles ->missed based on the value of ret, the common-case lock-held
code can be collapsed into a single "if" statement with a single-statement
"then" clause.

Yes, we could go further and just assign the "if" condition to ret,
but in the immortal words of MSDOS, "Are you sure?".

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 bcda7c6..dcc063a 100644 (file)
--- a/lib/ratelimit.c
+++ b/lib/ratelimit.c
@@ -88,17 +88,10 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func)
                        }
                }
        }
-       if (burst) {
-               int n_left = atomic_read(&rs->rs_n_left);
 
-               /* The burst might have been taken by a parallel call. */
-
-               if (n_left > 0) {
-                       n_left = atomic_dec_return(&rs->rs_n_left);
-                       if (n_left >= 0)
-                               ret = 1;
-               }
-       }
+       /* Note that the burst might be taken by a parallel call. */
+       if (burst && atomic_read(&rs->rs_n_left) > 0 && atomic_dec_return(&rs->rs_n_left) >= 0)
+               ret = 1;
 
 unlock_ret:
        raw_spin_unlock_irqrestore(&rs->lock, flags);