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[2604:1380:45d1:ec00::1]) by mx.google.com with ESMTPS id j10-20020a0c9cca000000b0067f65b3857bsi2966442qvf.15.2024.01.12.07.46.46 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 12 Jan 2024 07:46:46 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-24818-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=s1VHfd28; spf=pass (google.com: domain of linux-kernel+bounces-24818-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-24818-ouuuleilei=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ny.mirrors.kernel.org (Postfix) with ESMTPS id B4F1E1C21779 for ; Fri, 12 Jan 2024 15:46:46 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6C3A873161; Fri, 12 Jan 2024 15:46:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="s1VHfd28" 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 C104D6EB4E; Fri, 12 Jan 2024 15:46:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 614ECC433C7; Fri, 12 Jan 2024 15:46:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705074391; bh=sqERbnaek2gOhofvXHUtaO6gMYEIXaSQNKqGujdSGJs=; h=From:To:Cc:Subject:Date:From; b=s1VHfd28XLMMWLH27XZJhQJuSKihUO2kfwK8Q0e4CcjbNWEo6bWpYb8hHvli79hrT 1bMHVu1vt2phOwgvIJx6pf2xfgxkfkqaZDf30YgovBRjdFihg5+XJkz07DoN0cvCua Uc+YI973ty5oeC08vyE8MGlx5EdAftM2sQ+x25fjKfpY3lczMAt9shiXT3vIbTadOm TpBtlk47uTEEowBQcN8t0RIC1YmFqMqfVIVl2I21/p0N39YO1U29x4Ylq3Dzs7aSCX Q43T+Lqx5CHF4D03Bwrk6P7yM1l6QtKsxLSceJE/9IwqmAm99oyDz5OwcOOOb6oavy 17LWod7r0pjWA== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Boqun Feng , Joel Fernandes , Neeraj Upadhyay , "Paul E . McKenney" , Uladzislau Rezki , rcu Subject: [PATCH 0/7] rcu: Fix expedited GP deadlock Date: Fri, 12 Jan 2024 16:46:14 +0100 Message-Id: <20240112154621.261852-1-frederic@kernel.org> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1787900101216824286 X-GMAIL-MSGID: 1787900101216824286 TREE04 can trigger a writer stall if run with memory pressure. This is due to a circular dependency between waiting for expedited grace period and polling on expedited grace period when workqueues go back to mayday serialization. Here is a proposal fix. Changes since v2 (no functional changes, just renames and reorganization): _ Move nocb cleanups to their own series _ Rename can_queue parameter to use_worker [2/7] _ Better explain the rename of the mutex [3/7] _ New commit with just code move to ease review [4/7] _ Comment declaration of the new rnp->exp_worker field [5/7] Thanks. Frederic Weisbecker (7): rcu/exp: Fix RCU expedited parallel grace period kworker allocation failure recovery rcu/exp: Handle RCU expedited grace period kworker allocation failure rcu: s/boost_kthread_mutex/kthread_mutex rcu/exp: Move expedited kthread worker creation functions above rcutree_prepare_cpu() rcu/exp: Make parallel exp gp kworker per rcu node rcu/exp: Handle parallel exp gp kworkers affinity rcu/exp: Remove rcu_par_gp_wq kernel/rcu/rcu.h | 5 -- kernel/rcu/tree.c | 175 +++++++++++++++++++++++++++------------ kernel/rcu/tree.h | 11 ++- kernel/rcu/tree_exp.h | 78 +++-------------- kernel/rcu/tree_plugin.h | 52 ++---------- 5 files changed, 142 insertions(+), 179 deletions(-)