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 0F7B0C433F5 for ; Wed, 2 Mar 2022 15:49:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241112AbiCBPuf (ORCPT ); Wed, 2 Mar 2022 10:50:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242436AbiCBPuL (ORCPT ); Wed, 2 Mar 2022 10:50:11 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DCD3E48E66 for ; Wed, 2 Mar 2022 07:49:06 -0800 (PST) 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 dfw.source.kernel.org (Postfix) with ESMTPS id D75DB61735 for ; Wed, 2 Mar 2022 15:49:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1A09CC004E1; Wed, 2 Mar 2022 15:49:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646236145; bh=2VDUvcEwCsllnDBe7ipIo2e+Ud0/ufJ0n1ICl+dEAtM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VsG2+xVCpCoAVWqgWfvgs7rkNLIx+ua/P3troHf6UzPuLYrUGUTv01nH0qyWDjCif YUvWJtqKWLvAD39h9qgVSS99CErge3C9+Hz8Wt67w5tjtc2IVsjla4WnU+4x6/dxbP dv5lkptgABolUNEcSMtFduKji1D+g+P0yxRFf9CbkFawDPHlUBKk77lT0Dc95m0TEr Ovaojr9ieZVfkbuvcBNssBTwUXHPXSMV4udB6RsCiMN62/cYkn1+Hr6uqNCMaIYe2s vfi0PAaziTlubAlcAmNAJ6yexRags+h5/c+Fl5x9OAQuY4cGm/Zy6Id4pee+6aXCbW 4ABOkFaPlMnUw== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Peter Zijlstra , Phil Auld , Alex Belits , Nicolas Saenz Julienne , Xiongfeng Wang , Neeraj Upadhyay , Thomas Gleixner , Yu Liao , Boqun Feng , "Paul E . McKenney" , Marcelo Tosatti , Paul Gortmaker , Uladzislau Rezki , Joel Fernandes Subject: [PATCH 13/19] rcu/context-tracking: Move deferred nocb resched to context tracking Date: Wed, 2 Mar 2022 16:48:04 +0100 Message-Id: <20220302154810.42308-14-frederic@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220302154810.42308-1-frederic@kernel.org> References: <20220302154810.42308-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To prepare for migrating the RCU eqs accounting code to context tracking, split the last-resort deferred nocb resched from rcu_user_enter() and move it into a separate call from context tracking. Signed-off-by: Frederic Weisbecker Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Neeraj Upadhyay Cc: Uladzislau Rezki Cc: Joel Fernandes Cc: Boqun Feng Cc: Nicolas Saenz Julienne Cc: Marcelo Tosatti Cc: Xiongfeng Wang Cc: Yu Liao Cc: Phil Auld Cc: Paul Gortmaker Cc: Alex Belits --- include/linux/rcutree.h | 6 ++++++ kernel/context_tracking.c | 8 ++++++++ kernel/rcu/tree.c | 15 ++------------- 3 files changed, 16 insertions(+), 13 deletions(-) diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index e05334c4c3d1..6d111a3c0cc0 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -78,4 +78,10 @@ int rcutree_dead_cpu(unsigned int cpu); int rcutree_dying_cpu(unsigned int cpu); void rcu_cpu_starting(unsigned int cpu); +#if defined(CONFIG_NO_HZ_FULL) && (!defined(CONFIG_GENERIC_ENTRY) || !defined(CONFIG_KVM_XFER_TO_GUEST_WORK)) +void rcu_irq_work_resched(void); +#else +static inline void rcu_irq_work_resched(void) { } +#endif + #endif /* __LINUX_RCUTREE_H */ diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index 155534c409fc..7be7a2044d3a 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -60,6 +60,8 @@ static __always_inline void context_tracking_recursion_exit(void) */ void noinstr __ct_user_enter(enum ctx_state state) { + lockdep_assert_irqs_disabled(); + /* Kernel threads aren't supposed to go to userspace */ WARN_ON_ONCE(!current->mm); @@ -81,6 +83,12 @@ void noinstr __ct_user_enter(enum ctx_state state) vtime_user_enter(current); instrumentation_end(); } + /* + * Other than generic entry implementation, we may be past the last + * rescheduling opportunity in the entry code. Trigger a self IPI + * that will fire and reschedule once we resume in user/guest mode. + */ + rcu_irq_work_resched(); rcu_user_enter(); } /* diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index c2528e65de0c..938537958c27 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -686,7 +686,7 @@ static DEFINE_PER_CPU(struct irq_work, late_wakeup_work) = * last resort is to fire a local irq_work that will trigger a reschedule once IRQs * get re-enabled again. */ -noinstr static void rcu_irq_work_resched(void) +noinstr void rcu_irq_work_resched(void) { struct rcu_data *rdp = this_cpu_ptr(&rcu_data); @@ -702,10 +702,7 @@ noinstr static void rcu_irq_work_resched(void) } instrumentation_end(); } - -#else -static inline void rcu_irq_work_resched(void) { } -#endif +#endif /* #if !defined(CONFIG_GENERIC_ENTRY) || !defined(CONFIG_KVM_XFER_TO_GUEST_WORK) */ /** * rcu_user_enter - inform RCU that we are resuming userspace. @@ -720,14 +717,6 @@ static inline void rcu_irq_work_resched(void) { } */ noinstr void rcu_user_enter(void) { - lockdep_assert_irqs_disabled(); - - /* - * Other than generic entry implementation, we may be past the last - * rescheduling opportunity in the entry code. Trigger a self IPI - * that will fire and reschedule once we resume in user/guest mode. - */ - rcu_irq_work_resched(); rcu_eqs_enter(true); } -- 2.25.1