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 8E6291E52D 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=tGmj7fdhP+1CliJetDA1/cJYYW7IBVkeKksLxAfHbhag4+6sABp9C7LY8zJnqLsiH9qj91BiPobJ/jjfncwqonYr05tSa34n+r77FzYhhwyxIDOuJimeW8uvhI7rNW3yfeg+8HNkJ9WspuFQGUGpTCHHdkLxEq5L+iOZ1h+GlmQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745540908; c=relaxed/simple; bh=Ce2sLj777H7UVtPVPiiOrIAzDc+hCANvrpDCmS+t+HA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=SwSsHycLsICUSXlfZkotkdmWjtEswp/To3uPgFYNyVn6uXm4ninm3XeygaTdbuJ4ePQMUD5Jk2ny2OJFBIbdEZsMARxnzSLa3+0f5bHVGIVv+4MyxR5gi221Ww6YXT4dnb6BrfDOE7IfqApW0mMKeCmAkKiPsCi6p+MZFeJR168= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tun2kNSr; 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="tun2kNSr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D54AC4CEEC; 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=Ce2sLj777H7UVtPVPiiOrIAzDc+hCANvrpDCmS+t+HA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tun2kNSrJaaLiGgUF954UnBGMrn6AMjNuFV+tSSRJTZMISj4HPjcKsxROb/kVfyYN MmargbAp1nb8x28Bv6Bh9U8+LclSsFcxdVTMufNKPDuOzrO9h+6QkR6CxZHYt/0PyB c8pz/tq2WddwRyAeqSwpS4+LPOLOz3e93gmvXfvT3IqAl9I4GgisySIOtT4vxIwhdx bafmFvCZ07tQHsx8IO/nOnnkzQVgJR/hyz1/DrH22zPlYN0F6mmko4BJXHDOZ1DgX1 mmOj/Y/J3JVqCsRZGRcUQ09n+ho17scLK89iSJpuEbuZOnZz9iE+0FM7l1HPGTOAIn fEyVZQd33RNyA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 55FFCCE1DD5; 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 19/20] ratelimit: Use nolock_ret restructuring to collapse common case code Date: Thu, 24 Apr 2025 17:28:25 -0700 Message-Id: <20250425002826.3431914-19-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 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 Cc: Petr Mladek Cc: Andrew Morton Cc: Kuniyuki Iwashima Cc: Mateusz Guzik Cc: Steven Rostedt Cc: John Ogness Cc: Sergey Senozhatsky --- lib/ratelimit.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/lib/ratelimit.c b/lib/ratelimit.c index 7bbc270b88e21..768f26790ea9a 100644 --- 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); -- 2.40.1