From 743a1942d52f6827d39d8f6745d006b5bb8bbe6b Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 24 Apr 2025 12:16:21 -0700 Subject: [PATCH] ratelimit: Use nolock_ret label to collapse lock-failure code Now that we have a nolock_ret label that handles ->missed correctly based on the value of ret, we can eliminate a local variable and collapse several "if" statements on the lock-acquisition-failure code path. 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 Reviewed-by: Petr Mladek Cc: Andrew Morton Cc: Kuniyuki Iwashima Cc: Mateusz Guzik Cc: Steven Rostedt Cc: John Ogness Cc: Sergey Senozhatsky --- lib/ratelimit.c | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-) diff --git a/lib/ratelimit.c b/lib/ratelimit.c index e7101a79c6973..bcda7c61fc6ff 100644 --- a/lib/ratelimit.c +++ b/lib/ratelimit.c @@ -58,20 +58,10 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func) * the current lock owner is just about to reset it. */ if (!raw_spin_trylock_irqsave(&rs->lock, flags)) { - unsigned int rs_flags = READ_ONCE(rs->flags); - - if (rs_flags & RATELIMIT_INITIALIZED && burst) { - int n_left = atomic_read(&rs->rs_n_left); - - if (n_left <= 0) - return 0; - n_left = atomic_dec_return(&rs->rs_n_left); - if (n_left >= 0) - return 1; - } - - ratelimit_state_inc_miss(rs); - return 0; + if (READ_ONCE(rs->flags) & RATELIMIT_INITIALIZED && burst && + atomic_read(&rs->rs_n_left) > 0 && atomic_dec_return(&rs->rs_n_left) >= 0) + ret = 1; + goto nolock_ret; } if (!(rs->flags & RATELIMIT_INITIALIZED)) { -- 2.47.2