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 8722B2D023 for ; Wed, 30 Apr 2025 01:05:27 +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=1745975127; cv=none; b=h82lifHC1Lx6OYDyHsx73pdI3hC1hhqjFXByeqvxBh7sDKqrFe1g2YlgI59lcCG+kcdyPlWfK9y6ZBUqaF9Jx/A7lXSYCGJlTcYMmiEC+htFFgH9EpoPlquka3bNZIHE1oO2R+MGidCUvNGIIxqUfhcee0xBZyxyrgaGzR865g8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745975127; c=relaxed/simple; bh=IXjNK7JRbzJgmjpzWE0gJOfavJOhfRMhhLqkx9ULkFU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=pfzrHl5m5DWvoXQK6ckFNyvpUctiJwCvdecZBpOCMKHwttS9w9s1dEzhCrChXq8tx0irt4CgIkTF2tFGs3T6lHufQ7+WvkAzvMFUQ6Sdde65cUtUQj71j1bItbRgJCp7ApR39Xxp9SuVOpDPGcEexLrnR6ETpaEZ2uprgTWe7Vk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KIcblsI2; 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="KIcblsI2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63381C4CEFB; Wed, 30 Apr 2025 01:05:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745975127; bh=IXjNK7JRbzJgmjpzWE0gJOfavJOhfRMhhLqkx9ULkFU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KIcblsI2Thiw3KwUc4uQV9D+bH31MxD4Q/fy/cyDIjHqUH4UivV8acnosJCs6svyT aQxQjHCLrM9N6BGdUHHazFIy6CD8PcLwdGOO02MCZGRLdsBkN2u3I78nGq/fwl5eKg 4d93AxvDzXmxlBzmYbI4UaekIpvHe8JXtkQMcESfiAV8CifItH5ZilVHRhXpWjX8oC 3wSLgIQ8LYMQQg7y18IKFzM1lB0YwoKVxG47giUBt0+cgCJKQbrxSUkel9XW4Bh09e P4N8ARg1neePR1SNbYtLWLUhyGZvonKUOb14hxVqPNkOwCpBrCakSdtK0BQMxDSS/d +f1DHBJj8ALpA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id DA53ACE11CD; Tue, 29 Apr 2025 18:05:25 -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 v4 18/20] ratelimit: Use nolock_ret label to collapse lock-failure code Date: Tue, 29 Apr 2025 18:05:22 -0700 Message-Id: <20250430010524.3614408-18-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: 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 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)) { -- 2.40.1