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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA838C433F5 for ; Fri, 18 Mar 2022 08:06:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233339AbiCRIIL (ORCPT ); Fri, 18 Mar 2022 04:08:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233358AbiCRIIA (ORCPT ); Fri, 18 Mar 2022 04:08:00 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64ED4231936; Fri, 18 Mar 2022 01:06:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1647590802; x=1679126802; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=wwp1j4OGk9F57hN1np0w7mtBafinWSVg7Jz/pfT+Xe8=; b=YhU4YfKqYvXIgAEEkhPgWM5wofqzaVYYphzWESC+7gVLsQfZuDkGxxDl 1Y0iSNWt3f9fTVNrESbxcEZoIg/rlv/gw5Eg+utSyplA0KYMXxNNmAB68 LoYk1S0xsb/u/bpiEvphsLbQ67plogbLBkkfUpSi7WT70i04E1RHbDuQE Ld5IQwgIkjYdzF7kFgbms0Te+I+zCNHLWht2bNS1jXgFtjQj+D6v/pQTS UDNVUYe0ZulZIPNB0Z2+NTARYb8cPsFZeEu5041ydari1JAh2gJfog7nW qhxQgheRAOStDXZbnIbb5KdUbZcuRLYcCGAg6gswWVJ5qaTbaNRtRnSvH A==; X-IronPort-AV: E=McAfee;i="6200,9189,10289"; a="255917333" X-IronPort-AV: E=Sophos;i="5.90,191,1643702400"; d="scan'208";a="255917333" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2022 01:06:41 -0700 X-IronPort-AV: E=Sophos;i="5.90,191,1643702400"; d="scan'208";a="541734757" Received: from zq-optiplex-7090.bj.intel.com ([10.238.156.125]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Mar 2022 01:06:39 -0700 From: Zqiang To: paulmck@kernel.org, frederic@kernel.org Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 0/2] rcu: Deoffload rdp if rcuop/rcuog kthreads spawn failed Date: Fri, 18 Mar 2022 16:07:17 +0800 Message-Id: <20220318080719.1501471-1-qiang1.zhang@intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When CONFIG_RCU_NOCB_CPU is enabled and 'rcu_nocbs' is set, the rcuop and rcuog kthreads is created. however the rcuop or rcuog kthreads creation may fail, if failed, deoffload the offloaded rdp. --- v1->v2: Invert the locking dependency order between rcu_state.barrier_mutex and hotplug lock. Holding nocb_gp_kthread_mutex, ensure that the nocb_gp_kthread exists. v2->v3: Adjust the position of the nocb_gp_kthread_mutex, in rdp_gp->nocb_gp_kthread check upper lock nocb_gp_kthread_mutex. Do the locking order change in a separate patch. Zqiang(2): rcu: Call rcu_nocb_rdp_deoffload() directly after rcuog/op kthreads spawn failed rcu: Invert the locking dependency order between rcu_state.barrier_mutex and hotplug lock kernel/rcu/tree_nocb.h | 83 ++++++++++++++++++++++++++++++++---------- 1 file changed, 63 insertions(+), 20 deletions(-) -- 2.25.1