From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6350B18027 for ; Fri, 25 Apr 2025 00:28:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745540908; cv=none; b=cfn/Salbuq+hD2KOUlX++YayvqZbEz8gXhJW2xEUEtdOL8aufLv1VREdgp3yPHLzvCIYmBixFOolXJ+V6rpk3U4SbNvwpLu31X8BTznLkBLEU0q6JSSbEI7De39EqxKOWINbeVJdAOieBljwdbQJJTMlIFshQDAWHwkRzD89rCo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745540908; c=relaxed/simple; bh=CPkTM9i04f9X4QEWTixfTb/RCavIqHx07+QmRCayqpE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ukNi0DObKple1SgHAZlwt1IUJ/EqlG22xw3ek+1SNxkROLpfveXBAi+EEPIeEvBCc7j6Db8ArGG+oVJ3rozK0gMFZ+Hpaia9Oajx7DbD++DC+1bhXdA/RgSH4ih8AZtFpvPbm0VWy0OhIn8ghcUveRI/VOAAyZ+l7XtszdhXNUk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gJCUBx69; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gJCUBx69" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35872C4CEF1; Fri, 25 Apr 2025 00:28:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745540908; bh=CPkTM9i04f9X4QEWTixfTb/RCavIqHx07+QmRCayqpE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gJCUBx6954vJcoYj0FlS5qQcBQfbOQ/Uh6+abHOcsCYGpX5exh8wySrGK8qTwJwuU xuXjXoLHOnB5wkQFTsIh3Prwdwje4VwR/L8FDCaEjXhOt8zNOsQOnW7gQFoCaoJW6T 2mbeBa0IQup1SiD8VD8hDRAIDpmtS/K7rk9NCaXakNifREKISqfLc1TA9jtU4jQ2cZ MePS+gO+fpEESWTs1gropJGe71NhYmRB+TZ7EdICa2Kkku0wBkDOpYIUqUh2qPrDpZ J895m+VqWCqqUYao5eu1U4+VINrbv6/OEkLuat0Hrn4cQq7HkpIfgkL6QuX5Y0UalK WcHtfYCzlzyBw== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 532F6CE1DCE; Thu, 24 Apr 2025 17:28:27 -0700 (PDT) From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: kernel-team@meta.com, Andrew Morton , Kuniyuki Iwashima , Mateusz Guzik , Petr Mladek , Steven Rostedt , John Ogness , Sergey Senozhatsky , Jon Pan-Doh , Bjorn Helgaas , Karolina Stolarek , "Paul E. McKenney" Subject: [PATCH v3 18/20] ratelimit: Use nolock_ret label to collapse lock-failure code Date: Thu, 24 Apr 2025 17:28:24 -0700 Message-Id: <20250425002826.3431914-18-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <72ee57b8-9e2a-4cad-aaa0-1e3353d146d8@paulmck-laptop> References: <72ee57b8-9e2a-4cad-aaa0-1e3353d146d8@paulmck-laptop> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 Cc: 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 7b075654e23ac..7bbc270b88e21 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)) { -- 2.40.1