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 1CB32C433EF for ; Mon, 14 Mar 2022 13:38:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241896AbiCNNjV (ORCPT ); Mon, 14 Mar 2022 09:39:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33370 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241863AbiCNNjO (ORCPT ); Mon, 14 Mar 2022 09:39:14 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 498FC1119 for ; Mon, 14 Mar 2022 06:38:00 -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 64E8AB80DF4 for ; Mon, 14 Mar 2022 13:37:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 28375C340ED; Mon, 14 Mar 2022 13:37:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1647265078; bh=jk6umewZFxLd1Bf2B9rzTYEamkBtxaQMtyRXWqXjK5A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TKfpqy3ZScfBv4im+6QkVJ2j+hVA+h1uU3wriYMhuXUNZBxFRLWsePk0v1wZusbnX 0q0YFvXFwecwBCtTmJgWZOI/SsubvaBd5lpApSyErtV9tP4PGG7a4TDjz49QtWuZIG WzDJ1zmlXqWunGCdlDeo5jVbKjuOFv/52iSS+mI2uvuw6VFIvabFzglHiDiGoNyzoX tBnMMLWEETg3yI6TGrSEgXXTnl1ml10/7SXJfsSi27mTSvsbQ3Er0uODB5rSQrxEWr UHZgJEHjrJWjE7kdpAlYCPUkKLweEK2KRubcDMEJIObN61Qadhg8mnyvf934CI0NQS i1axDfgMDsBbg== From: Frederic Weisbecker To: "Paul E . McKenney" Cc: LKML , Valentin Schneider , Peter Zijlstra , Marco Elver , Neeraj Upadhyay , Frederic Weisbecker , Boqun Feng , Uladzislau Rezki , Joel Fernandes Subject: [PATCH 2/3] preempt/dynamic: Introduce preempt mode accessors Date: Mon, 14 Mar 2022 14:37:37 +0100 Message-Id: <20220314133738.269522-3-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220314133738.269522-1-frederic@kernel.org> References: <20220314133738.269522-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Valentin Schneider CONFIG_PREEMPT{_NONE, _VOLUNTARY} designate either: o The build-time preemption model when !PREEMPT_DYNAMIC o The default boot-time preemption model when PREEMPT_DYNAMIC IOW, using those on PREEMPT_DYNAMIC kernels is meaningless - the actual model could have been set to something else by the "preempt=foo" cmdline parameter. Introduce a set of helpers to determine the actual preemption mode used by the live kernel. Suggested-by: Marco Elver Signed-off-by: Valentin Schneider Signed-off-by: Frederic Weisbecker Cc: Uladzislau Rezki Cc: Joel Fernandes Cc: Boqun Feng Cc: Peter Zijlstra Cc: Neeraj Upadhyay --- include/linux/sched.h | 16 ++++++++++++++++ kernel/sched/core.c | 11 +++++++++++ 2 files changed, 27 insertions(+) diff --git a/include/linux/sched.h b/include/linux/sched.h index 508b91d57470..d348e886e4d0 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2096,6 +2096,22 @@ static inline void cond_resched_rcu(void) #endif } +#ifdef CONFIG_PREEMPT_DYNAMIC + +extern bool preempt_mode_none(void); +extern bool preempt_mode_voluntary(void); +extern bool preempt_mode_full(void); + +#else + +#define preempt_mode_none() IS_ENABLED(CONFIG_PREEMPT_NONE) +#define preempt_mode_voluntary() IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY) +#define preempt_mode_full() IS_ENABLED(CONFIG_PREEMPT) + +#endif + +#define preempt_mode_rt() IS_ENABLED(CONFIG_PREEMPT_RT) + /* * Does a critical section need to be broken due to another * task waiting?: (technically does not depend on CONFIG_PREEMPTION, diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2e4ae00e52d1..6e5c8f0f874a 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6684,6 +6684,17 @@ static void __init preempt_dynamic_init(void) } } +#define PREEMPT_MODE_ACCESSOR(mode) \ + bool preempt_mode_##mode(void) \ + { \ + WARN_ON_ONCE(preempt_dynamic_mode == preempt_dynamic_undefined); \ + return preempt_dynamic_mode == preempt_dynamic_##mode; \ + } + +PREEMPT_MODE_ACCESSOR(none) +PREEMPT_MODE_ACCESSOR(voluntary) +PREEMPT_MODE_ACCESSOR(full) + #else /* !CONFIG_PREEMPT_DYNAMIC */ static inline void preempt_dynamic_init(void) { } -- 2.25.1