From patchwork Wed Oct 9 12:51:17 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Neeraj Upadhyay X-Patchwork-Id: 13828396 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 989B7191F74; Wed, 9 Oct 2024 12:51:43 +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=1728478303; cv=none; b=YMXWcc566Ybbkiez/ZC5tCWNy0m70dFnJqCjPmavINCDc6iTxHbwp8BCVgJ47hRhi3Vb1WLP7nY8vUe2N4tyTu5fKsF/PH9LfC13j+smtUwXjvm2SbNGR6pT57zBAYuF+MOklQ27JCZ9vaELJqkUAcdmilJa3N/djFJh/xaQZsY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728478303; c=relaxed/simple; bh=tly/MWZa0oRwFhms5sXnxLza3S15ZekHONwA8y2aC14=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=f6jDgEAIOe8bIlrrp76kyO0BfVlfhZaxIP+niDl5SqGOD5eLRqSNLyOgxiZPZ7SSNpcI+Cw+Svbo7K9TIL6tCYl+Ig+6WeeBULTHRZ4LqByI8Ew38DBdgyyY0JN2to0WDt4PdUWmaPtANY+PmSozI4N8++4Z+2aS7ZsdLpf5lm8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OhsulU5g; 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="OhsulU5g" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9B4CC4CEC5; Wed, 9 Oct 2024 12:51:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728478303; bh=tly/MWZa0oRwFhms5sXnxLza3S15ZekHONwA8y2aC14=; h=From:To:Cc:Subject:Date:From; b=OhsulU5gMWY2KUpsQ+d4mPHopGIcxIKSaTFrcQvM5tm48hpFaIhzK1okWJbCNvwN7 891YvaBt/K3Qr5r9zamr1xzW5kkuuJfUh/DLU96gxZ+Vpw8PLv34RFa9wayohY0Z5w GQlUnLtyXhJIvKEZ98ypfU6IOpWcIVH5E49BR8bXnyCNZF6K8Kz60NhjlSnKO89hwk cF/Gme5eYTUwxCpLgYZwvd+ZHJz6mTMTwQXq0lf9pZ8zF6X3vyPVoe39f5044TtMJF CdD905g60v1cLx5R8W3fMzqW20F1ZiYcNDDw/i5jiuKGs0qBjNb+iUzbiM/2UfpOkG lF+7vw7/8BDYQ== From: neeraj.upadhyay@kernel.org To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, paulmck@kernel.org, joel@joelfernandes.org, frederic@kernel.org, boqun.feng@gmail.com, urezki@gmail.com, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, qiang.zhang1211@gmail.com, peterz@infradead.org, neeraj.upadhyay@amd.com, Neeraj Upadhyay Subject: [PATCH v2 00/10] Make RCU Tasks scan idle tasks Date: Wed, 9 Oct 2024 18:21:17 +0530 Message-Id: <20241009125127.18902-1-neeraj.upadhyay@kernel.org> X-Mailer: git-send-email 2.40.1 Precedence: bulk X-Mailing-List: rcu@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Neeraj Upadhyay Architectures for which all deep-idle and entry-exit functions are marked noinstr, synchronize_rcu_tasks_rude() is not required. However, disabling synchronize_rcu_tasks_rude() for such architectures require RCU-tasks to pay attention to idle tasks until they enter the context where RCU is not watching. In addition, NMI context need to track RCU-tasks entry/exit for NO_HZ_FULL CPUs. This series adds changes for both of these requirements. The series is available in git tree at: https://git.kernel.org/pub/scm/linux/kernel/git/neeraj.upadhyay/linux-rcu.git/log/?h=rcu.tasks.idle Changes since v1: https://lore.kernel.org/lkml/20240807163506.434885-1-neeraj.upadhyay@kernel.org/ - Split into multiple patches (Paul) - Various restructuring updates (Frederic) - Fix race with early boot code (Frederic) - Check RCU watching state for idle injection tasks. - Include patch to turn synchronize_rcu_tasks_rude() into noop for architectures with CONFIG_ARCH_WANTS_NO_INSTR enabled. Neeraj Upadhyay (9): rcu: Change rdp arg to cpu number for rcu_watching_snap_stopped_since() rcu: Make some rcu_watching_* functions global rcu/tasks: Move holdout checks for idle task to a separate function rcu/tasks: Create rcu_idle_task_is_holdout() definition for !SMP rcu/tasks: Consider idle tasks not running on CPU as non-holdouts rcu/tasks: Check RCU watching state for holdout idle tasks rcu/tasks: Check RCU watching state for holdout idle injection tasks rcu/tasks: Make RCU-tasks pay attention to idle tasks context_tracking: Invoke RCU-tasks enter/exit for NMI context Paul E. McKenney (1): rcu: Allow short-circuiting of synchronize_rcu_tasks_rude() .../RCU/Design/Requirements/Requirements.rst | 12 +- kernel/context_tracking.c | 11 +- kernel/rcu/rcu.h | 4 + kernel/rcu/tasks.h | 148 ++++++++++++++---- kernel/rcu/tree.c | 16 +- kernel/rcu/tree_exp.h | 2 +- 6 files changed, 140 insertions(+), 53 deletions(-)