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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 62627C433F5 for ; Fri, 15 Oct 2021 09:44:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40BC8611BD for ; Fri, 15 Oct 2021 09:44:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237588AbhJOJrE (ORCPT ); Fri, 15 Oct 2021 05:47:04 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:48858 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237633AbhJOJrC (ORCPT ); Fri, 15 Oct 2021 05:47:02 -0400 Date: Fri, 15 Oct 2021 09:44:54 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1634291095; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oN6nRiS11eEBGxmyF+O4CRrePqYJgkPxbDWKEj4itSs=; b=LOgZV349HB5ogW6itBNlXQbPu1JY7urZWDtjSDDeRaTj2fHSo+neIjrWf1xXTh9w37HrFZ B6HtDdhOWe/SkRCBSX01o5OLg62JSID/4Hp8UYYtYPhjk9XX222cRKaPEjxFZNmjLXccV6 Ml6UF6H9i/ULfm9mPrJdTRhU2lS2GQDbqHJGqevRk5VHxDKgDAoVZCPCPXyaGAOhqrvENG qJONjK/HbwEsVHm0nF6lzbenHK5XFQ1m4Poa6ovuZJNQ9GdxzfMbN+xAQ5XH+zLjFcIxfj qWGrsOD21S0xzr4n3j/+U1/27cFz/0ma1+rKT04i7YuCS2z3PpN3+K3M8Aen3Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1634291095; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oN6nRiS11eEBGxmyF+O4CRrePqYJgkPxbDWKEj4itSs=; b=L1hAg7mdQGip3pIbqCFUS7xjHeFXCn4XCT2PSWE3l1ek/pzdGNgZYqPMLpd8KGwhfQ1Rk2 4jfejftz6Gfbc+Bw== From: "tip-bot2 for Sebastian Andrzej Siewior" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT Cc: Sebastian Andrzej Siewior , "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20211006111852.1514359-5-bigeasy@linutronix.de> References: <20211006111852.1514359-5-bigeasy@linutronix.de> MIME-Version: 1.0 Message-ID: <163429109409.25758.10980405022488264190.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/core branch of tip: Commit-ID: 09089db79859cbccccd8df95b034f36f7027efa6 Gitweb: https://git.kernel.org/tip/09089db79859cbccccd8df95b034f36f7027efa6 Author: Sebastian Andrzej Siewior AuthorDate: Wed, 06 Oct 2021 13:18:52 +02:00 Committer: Peter Zijlstra CommitterDate: Fri, 15 Oct 2021 11:25:18 +02:00 irq_work: Also rcuwait for !IRQ_WORK_HARD_IRQ on PREEMPT_RT On PREEMPT_RT most items are processed as LAZY via softirq context. Avoid to spin-wait for them because irq_work_sync() could have higher priority and not allow the irq-work to be completed. Wait additionally for !IRQ_WORK_HARD_IRQ irq_work items on PREEMPT_RT. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20211006111852.1514359-5-bigeasy@linutronix.de --- include/linux/irq_work.h | 5 +++++ kernel/irq_work.c | 6 ++++-- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h index b48955e..8cd11a2 100644 --- a/include/linux/irq_work.h +++ b/include/linux/irq_work.h @@ -49,6 +49,11 @@ static inline bool irq_work_is_busy(struct irq_work *work) return atomic_read(&work->node.a_flags) & IRQ_WORK_BUSY; } +static inline bool irq_work_is_hard(struct irq_work *work) +{ + return atomic_read(&work->node.a_flags) & IRQ_WORK_HARD_IRQ; +} + bool irq_work_queue(struct irq_work *work); bool irq_work_queue_on(struct irq_work *work, int cpu); diff --git a/kernel/irq_work.c b/kernel/irq_work.c index 90b6b56..f7df715 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -217,7 +217,8 @@ void irq_work_single(void *arg) */ (void)atomic_cmpxchg(&work->node.a_flags, flags, flags & ~IRQ_WORK_BUSY); - if (!arch_irq_work_has_interrupt()) + if ((IS_ENABLED(CONFIG_PREEMPT_RT) && !irq_work_is_hard(work)) || + !arch_irq_work_has_interrupt()) rcuwait_wake_up(&work->irqwait); } @@ -277,7 +278,8 @@ void irq_work_sync(struct irq_work *work) lockdep_assert_irqs_enabled(); might_sleep(); - if (!arch_irq_work_has_interrupt()) { + if ((IS_ENABLED(CONFIG_PREEMPT_RT) && !irq_work_is_hard(work)) || + !arch_irq_work_has_interrupt()) { rcuwait_wait_event(&work->irqwait, !irq_work_is_busy(work), TASK_UNINTERRUPTIBLE); return;