From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD299C43463 for ; Mon, 21 Sep 2020 12:44:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BD5220EDD for ; Mon, 21 Sep 2020 12:44:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600692283; bh=lERr2kpMpC1vWfRV40MQ57Rp2Y00l8Xn2wmNQsCq+3M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=N3uTDHbaZRfbRpFgkJYZ7AbabokV4R0/ZT2jNGVUmq0aD6ISQ5xjCqgUkJgzeXrNV TYLB1qrivD8165QqlBvl2oSFtUzptTOkAVgYyKvnK4cuxMH+qfgvysnHJnqkscU7F9 1KoXbsPcAvFOq9N7cmPyrBJfIdk+5hsAESuQsRUc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727109AbgIUMol (ORCPT ); Mon, 21 Sep 2020 08:44:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:54770 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726501AbgIUMoY (ORCPT ); Mon, 21 Sep 2020 08:44:24 -0400 Received: from lenoir.home (lfbn-ncy-1-588-162.w81-51.abo.wanadoo.fr [81.51.203.162]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9AD40221EC; Mon, 21 Sep 2020 12:44:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600692262; bh=lERr2kpMpC1vWfRV40MQ57Rp2Y00l8Xn2wmNQsCq+3M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lzUs/3J+RvlEdbQBQjD81p0lBSewLkIN7n6/50IXhmlBkqlBv21in1qxjlm/yh77Z oKWKNike0yO3IrENNXv+k/ASyNuCLd/AWJfNACiwJEHvZYZvcebqz1F4Hhn59ydrPW PHzK+8OgRKbozpcUgkxcEWrOgrHZd9J249XAbvVU= From: Frederic Weisbecker To: "Paul E . McKenney" Cc: LKML , Frederic Weisbecker , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , Josh Triplett Subject: [RFC PATCH 12/12] rcu: Nocb (de)activate through sysfs Date: Mon, 21 Sep 2020 14:43:51 +0200 Message-Id: <20200921124351.24035-13-frederic@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200921124351.24035-1-frederic@kernel.org> References: <20200921124351.24035-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Not for merge. Make nocb toggable for a given CPU using: /sys/devices/system/cpu/cpu*/hotplug/nocb This is only intended for those who want to test this patchset. The real interfaces will be cpuset/isolation and rcutorture. Not-Signed-off-by: Frederic Weisbecker Cc: Paul E. McKenney Cc: Josh Triplett Cc: Steven Rostedt Cc: Mathieu Desnoyers Cc: Lai Jiangshan Cc: Joel Fernandes --- kernel/cpu.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/kernel/cpu.c b/kernel/cpu.c index 6ff2578ecf17..a36634113b8e 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -2224,10 +2224,33 @@ static ssize_t show_cpuhp_fail(struct device *dev, static DEVICE_ATTR(fail, 0644, show_cpuhp_fail, write_cpuhp_fail); +static ssize_t write_nocb(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int val, ret; + + ret = kstrtoint(buf, 10, &val); + if (ret) + return ret; + + if (val == 0) + rcu_nocb_cpu_deoffload(dev->id); + else if (val == 1) + rcu_nocb_cpu_offload(dev->id); + else + return -EINVAL; + + return count; +} + +static DEVICE_ATTR(nocb, 0644, NULL, write_nocb); + static struct attribute *cpuhp_cpu_attrs[] = { &dev_attr_state.attr, &dev_attr_target.attr, &dev_attr_fail.attr, + &dev_attr_nocb.attr, NULL }; -- 2.28.0