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 372F1C433F5 for ; Tue, 19 Apr 2022 00:13:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239396AbiDSAPp (ORCPT ); Mon, 18 Apr 2022 20:15:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238721AbiDSAPS (ORCPT ); Mon, 18 Apr 2022 20:15:18 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 451916311; Mon, 18 Apr 2022 17:12:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 01536B81123; Tue, 19 Apr 2022 00:12:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8AC5CC385A8; Tue, 19 Apr 2022 00:12:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1650327154; bh=ekqEEHkIZKPJH+WeMu+2eIAZrk4ZMTg5yBKQBCNK+yQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ihCPdbN3zo0cP8d3WEi8YefeEUDMZxLEo9I3SY7xDI112BGXxwNDYgWZezawexwQW cWtOX8xKuMQ/uZYNoiNfMl8QI0S5uirC+YALJxznLOhzf9wNfbZ+WZRssgnrGi9FAU zXggP660QOKKSHvWGfleilR+3OsnproDS7TtJGY5PJJyLVmly0UlGX8lOTiMam0dr8 6AqWr8DfL5qkfNPSlrSYfVV1fAY9e6nPiUsvgfjRMPHMh1/IqGE31CAUCiwrZVg9E3 mAwd0+irKnhl2DugPMe7H1DIHYKo7iE1vLPbnoUJ65LcGfnjHkrJ+2ne+Ce7efkF+Y wgJ6kYoxCL9Rg== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 4103D5C04C6; Mon, 18 Apr 2022 17:12:34 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, rostedt@goodmis.org, "Paul E. McKenney" , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Zhouyi Zhou , Andrii Nakryiko , Alexei Starovoitov , Mathieu Desnoyers , Masami Hiramatsu Subject: [PATCH rcu 02/12] rcu: Make the TASKS_RCU Kconfig option be selected Date: Mon, 18 Apr 2022 17:12:23 -0700 Message-Id: <20220419001233.3950188-2-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20220419001123.GA3949851@paulmck-ThinkPad-P17-Gen-1> References: <20220419001123.GA3949851@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, any kernel built with CONFIG_PREEMPTION=y also gets CONFIG_TASKS_RCU=y, which is not helpful to people trying to build preemptible kernels of minimal size. Because CONFIG_TASKS_RCU=y is needed only in kernels doing tracing of one form or another, this commit moves from TASKS_RCU deciding when it should be enabled to the tracing Kconfig options explicitly selecting it. This allows building preemptible kernels without TASKS_RCU, if desired. This commit also updates the SRCU-N and TREE09 rcutorture scenarios in order to avoid Kconfig errors that would otherwise result from CONFIG_TASKS_RCU being selected without its CONFIG_RCU_EXPERT dependency being met. [ paulmck: Apply BPF_SYSCALL feedback from Andrii Nakryiko. ] Reported-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Tested-by: Zhouyi Zhou Cc: Andrii Nakryiko Cc: Alexei Starovoitov Cc: Steven Rostedt Cc: Mathieu Desnoyers Cc: Masami Hiramatsu Signed-off-by: Paul E. McKenney --- Update SRCU-N and TREE09 to avoid Kconfig errors. Signed-off-by: Paul E. McKenney --- arch/Kconfig | 1 + kernel/bpf/Kconfig | 1 + kernel/rcu/Kconfig | 3 ++- kernel/trace/Kconfig | 1 + tools/testing/selftests/rcutorture/configs/rcu/SRCU-N | 2 ++ tools/testing/selftests/rcutorture/configs/rcu/TREE09 | 2 ++ 6 files changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/Kconfig b/arch/Kconfig index 29b0167c088b..1bf29ce754af 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -35,6 +35,7 @@ config KPROBES depends on MODULES depends on HAVE_KPROBES select KALLSYMS + select TASKS_RCU if PREEMPTION help Kprobes allows you to trap at almost any kernel address and execute a callback function. register_kprobe() establishes diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig index d56ee177d5f8..2dfe1079f772 100644 --- a/kernel/bpf/Kconfig +++ b/kernel/bpf/Kconfig @@ -27,6 +27,7 @@ config BPF_SYSCALL bool "Enable bpf() system call" select BPF select IRQ_WORK + select TASKS_RCU if PREEMPTION select TASKS_TRACE_RCU select BINARY_PRINTF select NET_SOCK_MSG if NET diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig index f559870fbf8b..4f665ae0cf55 100644 --- a/kernel/rcu/Kconfig +++ b/kernel/rcu/Kconfig @@ -78,7 +78,8 @@ config TASKS_RCU_GENERIC task-based RCU implementations. Not for manual selection. config TASKS_RCU - def_bool PREEMPTION + def_bool 0 + select IRQ_WORK help This option enables a task-based RCU implementation that uses only voluntary context switch (not preemption!), idle, and diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 2c43e327a619..bf5da6c4e999 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -144,6 +144,7 @@ config TRACING select BINARY_PRINTF select EVENT_TRACING select TRACE_CLOCK + select TASKS_RCU if PREEMPTION config GENERIC_TRACER bool diff --git a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N index 2da8b49589a0..07f5e0a70ae7 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N +++ b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N @@ -6,3 +6,5 @@ CONFIG_PREEMPT_NONE=y CONFIG_PREEMPT_VOLUNTARY=n CONFIG_PREEMPT=n #CHECK#CONFIG_RCU_EXPERT=n +CONFIG_KPROBES=n +CONFIG_FTRACE=n diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE09 b/tools/testing/selftests/rcutorture/configs/rcu/TREE09 index 8523a7515cbf..fc45645bb5f4 100644 --- a/tools/testing/selftests/rcutorture/configs/rcu/TREE09 +++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE09 @@ -13,3 +13,5 @@ CONFIG_DEBUG_LOCK_ALLOC=n CONFIG_RCU_BOOST=n CONFIG_DEBUG_OBJECTS_RCU_HEAD=n #CHECK#CONFIG_RCU_EXPERT=n +CONFIG_KPROBES=n +CONFIG_FTRACE=n -- 2.31.1.189.g2e36527f23