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 2691728368 for ; Wed, 15 Nov 2023 20:46:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="1lcZjImz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC0E5C433C8; Wed, 15 Nov 2023 20:46:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700081161; bh=BeqNORGcKWdYNrzgn4ycsLbZuMMNE3cr8PAZb//WP58=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1lcZjImz13A/OGDikxO9dIyrSwu+a7AVyrVDYtKcBpZjECtOWRrSsz77+3CNQ2/B1 9tgeB23zao7zK9645hwaq0hqvxK4IQOSLn+iBH7uGMtq1XBhxJ5pioysE1MDDCxIbe SAe8KzjhFMnF4yL5O1RrIWu4OmZzTKmMeima0B7c= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pavel Machek , Sasha Levin Subject: [PATCH 4.19 50/88] ledtrig-cpu: Limit to 8 CPUs Date: Wed, 15 Nov 2023 15:36:02 -0500 Message-ID: <20231115191429.167327925@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115191426.221330369@linuxfoundation.org> References: <20231115191426.221330369@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pavel Machek [ Upstream commit abcc131292aa8c7de2c5f0ed76a717436c21de63 ] Some machines have thousands of CPUs... and trigger mechanisms was not really meant for thousands of triggers. I doubt anyone uses this trigger on many-CPU machine; but if they do, they'll need to do it properly. Signed-off-by: Pavel Machek Stable-dep-of: ff50f5327613 ("leds: trigger: ledtrig-cpu:: Fix 'output may be truncated' issue for 'cpu'") Signed-off-by: Sasha Levin --- drivers/leds/trigger/ledtrig-cpu.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/leds/trigger/ledtrig-cpu.c b/drivers/leds/trigger/ledtrig-cpu.c index 66a6260919367..1fca1ad00c3b9 100644 --- a/drivers/leds/trigger/ledtrig-cpu.c +++ b/drivers/leds/trigger/ledtrig-cpu.c @@ -1,14 +1,18 @@ /* * ledtrig-cpu.c - LED trigger based on CPU activity * - * This LED trigger will be registered for each possible CPU and named as - * cpu0, cpu1, cpu2, cpu3, etc. + * This LED trigger will be registered for first 8 CPUs and named + * as cpu0..cpu7. There's additional trigger called cpu that + * is on when any CPU is active. + * + * If you want support for arbitrary number of CPUs, make it one trigger, + * with additional sysfs file selecting which CPU to watch. * * It can be bound to any LED just like other triggers using either a * board file or via sysfs interface. * * An API named ledtrig_cpu is exported for any user, who want to add CPU - * activity indication in their code + * activity indication in their code. * * Copyright 2011 Linus Walleij * Copyright 2011 - 2012 Bryan Wu @@ -149,6 +153,9 @@ static int __init ledtrig_cpu_init(void) for_each_possible_cpu(cpu) { struct led_trigger_cpu *trig = &per_cpu(cpu_trig, cpu); + if (cpu >= 8) + continue; + snprintf(trig->name, MAX_NAME_LEN, "cpu%d", cpu); led_trigger_register_simple(trig->name, &trig->_trig); -- 2.42.0