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=-10.3 required=3.0 tests=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 EDCBFC433DF for ; Wed, 13 May 2020 16:47:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4EDB4207C4 for ; Wed, 13 May 2020 16:47:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589388463; bh=9uD5GGq95GEOrIdgKq0RsYH4vkz3D0lu7+MGs0mk+O0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0bCk1/I5Ac8evVIPRszdlxakY1EDEM2wFTOl/a8441e0BKJxfmp51TLCm7i21rcx4 36eUl8Gi83g3yut3tmC1xgA2QekmpKwaUwPcBfEWvraWlh+e1kkQwfzh0L9wDVdmgd Qu78wpOl+/w2NC4tOcO28hNvgOgRLR3ZRZq5U5Xk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389787AbgEMQrm (ORCPT ); Wed, 13 May 2020 12:47:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:53734 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389779AbgEMQrj (ORCPT ); Wed, 13 May 2020 12:47:39 -0400 Received: from lenoir.home (lfbn-ncy-1-985-231.w90-101.abo.wanadoo.fr [90.101.63.231]) (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 9535E207CD; Wed, 13 May 2020 16:47:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589388459; bh=9uD5GGq95GEOrIdgKq0RsYH4vkz3D0lu7+MGs0mk+O0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SUGbaMdjR5Z5CqcYfNBX7cNUuwTss6vdSqc+h2r8BujPUbl6j+QZZc/7GgvQiZp5y TLq1308vIJXHtls1LekIvn2qUbVE7YbqzzQHFaGq/qdnsSNUgzZTWusMy7juX71II/ +YmnbXMqw43mDNPtEE5wvEhBDCtP/KWXryb5wEN0= From: Frederic Weisbecker To: "Paul E . McKenney" Cc: LKML , Frederic Weisbecker , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , Josh Triplett Subject: [PATCH 10/10] rcu: Nocb (de)activate through sysfs Date: Wed, 13 May 2020 18:47:14 +0200 Message-Id: <20200513164714.22557-11-frederic@kernel.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200513164714.22557-1-frederic@kernel.org> References: <20200513164714.22557-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org 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 2371292f30b0..ac6283dcb897 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -2208,10 +2208,33 @@ 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 }; -- 2.25.0