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 3ADABC433F5 for ; Tue, 19 Apr 2022 14:14:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345975AbiDSOQ5 (ORCPT ); Tue, 19 Apr 2022 10:16:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232268AbiDSOQt (ORCPT ); Tue, 19 Apr 2022 10:16:49 -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 3EF1439802; Tue, 19 Apr 2022 07:14:06 -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 E9DAEB811B9; Tue, 19 Apr 2022 14:14:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 521F5C385A7; Tue, 19 Apr 2022 14:14:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1650377643; bh=WECWMHh+I23LXcZzkz4DAIl7OQBINw7ymf0B3/Pj3z4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=BPHVqMf0U5PD45GpHJnmm3ExaaZ8Sal2p0G/rPP32sTa7pcEY3+0b+AAXj66/qP73 927GV+QSQQxYYSSyQLGmHwWDxBYW11JSWRlRCjQxdFVBuLYpUrxz+/7HIpLJ5b/x0T zAYCl7gdftcFC9HSNf3ExwIHLoa/Pcz7QUqVztAZsgzmre0v3kF/D2YiYAAU9SrWWn NTvHWdSusC878m7aaQ5OgInAkRKUEwRwJRB0wyCx+6noSF+m70Wuvj15gsek5b2z7B +GfeT9fr5PiRzk77bav9mEOytQhxAc2D+tuEYN/VtXCFhmjU7ZhNWxuzqIYogDrLom jfeJcO6z8HDnQ== Date: Tue, 19 Apr 2022 23:13:58 +0900 From: Masami Hiramatsu To: "Paul E. McKenney" Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, rostedt@goodmis.org, Hyeonggon Yoo <42.hyeyoo@gmail.com>, Zhouyi Zhou , Andrii Nakryiko , Alexei Starovoitov , Mathieu Desnoyers , Masami Hiramatsu Subject: Re: [PATCH rcu 02/12] rcu: Make the TASKS_RCU Kconfig option be selected Message-Id: <20220419231358.2a0517ee265296a25b4305be@kernel.org> In-Reply-To: <20220419001233.3950188-2-paulmck@kernel.org> References: <20220419001123.GA3949851@paulmck-ThinkPad-P17-Gen-1> <20220419001233.3950188-2-paulmck@kernel.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 18 Apr 2022 17:12:23 -0700 "Paul E. McKenney" wrote: > 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. Thanks for fixing this dependency. This looks good to me (for kprobe part) Acked-by: Masami Hiramatsu Thank you, > > [ 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 > -- Masami Hiramatsu