From patchwork Wed Oct 2 14:57:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frederic Weisbecker X-Patchwork-Id: 13819887 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 B93B12F44; Wed, 2 Oct 2024 14:57:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727881065; cv=none; b=My+tTUngGQ8vS5H+4tYw7Xj+t4DVbXHxv0Yvt20AxsX7OXrlvcV3VZqPv9KTGDSq5/Rj+jnZeLdUyERipeKl44I7ujZ4Pd+Lt8cCCmTu+wFvisB1buHMx6lLAHWoEcPd+V0MCfePiCMdE3ovnKAMYl5zEs7Zy/GKyT47V9x0r+A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727881065; c=relaxed/simple; bh=LQ+m8emgyeASgsohucqCHIH10ejXMfAdv2m9/v6FdLA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=h4iBwEXsuCsIlWUFN+OKZHTQ6N2t3fCiETZhiE14EVfxzCIDHdBhugUuICTit4yfYApup2cd//IbdTPW+0pvT3rLvMiubd8UoiWvdC9rFLRcYw/yLc3qFDNXb2PLmGUbzbWyFDJCw4GQg0/bJaGihxY0Gz0FOFSQTrNfqxuVi00= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VcXqt6s2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VcXqt6s2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 706F7C4CECE; Wed, 2 Oct 2024 14:57:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727881065; bh=LQ+m8emgyeASgsohucqCHIH10ejXMfAdv2m9/v6FdLA=; h=From:To:Cc:Subject:Date:From; b=VcXqt6s2L4lbRbUoeWo3EKyb1RktT799yPV50Sru8ZR/bzhx+lnD9vqEz54LOjfaf T8sgKW+ssvKI8CiUbzXRkMri+7llI+cFtQehcAxStd5X7NZis7N+02QUX8grXBlVVL Q7HFCEHoJ25eNKo15bsoYa5Igl0ecx28QhjZXgJT+EKCpzeHPA3twyJ9ZUS37RRJFB O7zuEkGDzTTobkoQpOcSp7j0fjUfRC2PDSh8BU3K2dEl6Y3i9fMfL+HP7/sEdk0bck z0p7YkeTvWzpljidMLaerwOdKJpj3P4Yj8SH2DkOz496MjukNaqo1/C+XJJtluOF6x T+9pE0GnyIAJQ== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Boqun Feng , Joel Fernandes , Neeraj Upadhyay , "Paul E . McKenney" , Uladzislau Rezki , Zqiang , rcu Subject: [PATCH 0/3] rcu: Fix yet another wake up from offline related issue Date: Wed, 2 Oct 2024 16:57:35 +0200 Message-ID: <20241002145738.38226-1-frederic@kernel.org> X-Mailer: git-send-email 2.46.0 Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Hi, A new warning has been reported due to swake_up_one_online() use from an offline IRQ: https://lore.kernel.org/oe-lkp/202409231644.4c55582d-lkp@intel.com Here is a tentative fix. Similar issue can happen with exp kthread and GP kthread if offline tick fires and there is a pending deferred quiescent state to report on PREEMPT_RCU. Currently only oneshot ticks are disabled while the CPU is offlining. I have yet to take care of the periodic tick implementation. Work in progress... Frederic Weisbecker (3): rcu/nocb: Use switch/case on NOCB timer state machine rcu/nocb: Fix rcuog wake-up from offline softirq rcu: Report callbacks enqueued on offline CPU blind spot kernel/rcu/tree.c | 3 +++ kernel/rcu/tree.h | 1 + kernel/rcu/tree_nocb.h | 47 +++++++++++++++++++++++++++++++----------- 3 files changed, 39 insertions(+), 12 deletions(-)