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 595288F40 for ; Sun, 16 Jul 2023 20:32:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A049C433C8; Sun, 16 Jul 2023 20:32:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689539528; bh=44wYcN7dU3HjPXSPPhoYLcbj/0dBYkBjyGKjKQzP/0M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mVj/sqtBL9BMDjsKCDNFBDnZe0u56bRUucjuwG96UDZLPKx3wcMH6gjORDJOYex4W 8Xe4U8LBs9hDMqvospSW3fEErBSLzDcgWPFhqvoWqFB/zHbqn5u3vbhocuvhpLIe4Y F35SisP3KlOpRH1WhTVIJHb6FSbwE7z9xaLQcfV4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Wen Yang , Thomas Gleixner , Sasha Levin Subject: [PATCH 6.1 039/591] tick/rcu: Fix bogus ratelimit condition Date: Sun, 16 Jul 2023 21:42:58 +0200 Message-ID: <20230716194924.891743169@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230716194923.861634455@linuxfoundation.org> References: <20230716194923.861634455@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Wen Yang [ Upstream commit a7e282c77785c7eabf98836431b1f029481085ad ] The ratelimit logic in report_idle_softirq() is broken because the exit condition is always true: static int ratelimit; if (ratelimit < 10) return false; ---> always returns here ratelimit++; ---> no chance to run Make it check for >= 10 instead. Fixes: 0345691b24c0 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle") Signed-off-by: Wen Yang Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/tencent_5AAA3EEAB42095C9B7740BE62FBF9A67E007@qq.com Signed-off-by: Sasha Levin --- kernel/time/tick-sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index d6fb6a676bbbb..1ad89eec2a55f 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -1046,7 +1046,7 @@ static bool report_idle_softirq(void) return false; } - if (ratelimit < 10) + if (ratelimit >= 10) return false; /* On RT, softirqs handling may be waiting on some lock */ -- 2.39.2