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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5BC2EC10DCE for ; Fri, 13 Mar 2020 17:47:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C5E3206E2 for ; Fri, 13 Mar 2020 17:47:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727306AbgCMRrq (ORCPT ); Fri, 13 Mar 2020 13:47:46 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:47731 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727146AbgCMRrY (ORCPT ); Fri, 13 Mar 2020 13:47:24 -0400 Received: from localhost ([127.0.0.1] helo=flow.W.breakpoint.cc) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1jCoP3-00017r-Dx; Fri, 13 Mar 2020 18:47:21 +0100 From: Sebastian Andrzej Siewior To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , Ingo Molnar , Will Deacon , "Paul E . McKenney" , Joel Fernandes , Steven Rostedt , Linus Torvalds , Thomas Gleixner , Sebastian Andrzej Siewior Subject: [PATCH 8/9] lockdep: Annotate irq_work Date: Fri, 13 Mar 2020 18:47:00 +0100 Message-Id: <20200313174701.148376-9-bigeasy@linutronix.de> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200313174701.148376-1-bigeasy@linutronix.de> References: <20200313174701.148376-1-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Mark irq_work items with IRQ_WORK_HARD_IRQ which should be invoked in hardirq context even on PREEMPT_RT. IRQ_WORK without this flag will be invoked in softirq context on PREEMPT_RT. Set ->irq_config to 1 for the IRQ_WORK items which are invoked in softirq context so lockdep knows that these can safely acquire a spinlock_t. Signed-off-by: Sebastian Andrzej Siewior --- include/linux/irq_work.h | 2 ++ include/linux/irqflags.h | 13 +++++++++++++ kernel/irq_work.c | 2 ++ kernel/rcu/tree.c | 1 + kernel/time/tick-sched.c | 1 + 5 files changed, 19 insertions(+) diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h index 02da997ad12ce..3b752e80c017d 100644 --- a/include/linux/irq_work.h +++ b/include/linux/irq_work.h @@ -18,6 +18,8 @@ =20 /* Doesn't want IPI, wait for tick: */ #define IRQ_WORK_LAZY BIT(2) +/* Run hard IRQ context, even on RT */ +#define IRQ_WORK_HARD_IRQ BIT(3) =20 #define IRQ_WORK_CLAIMED (IRQ_WORK_PENDING | IRQ_WORK_BUSY) =20 diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h index 9c17f9c827aac..f23f540e0ebba 100644 --- a/include/linux/irqflags.h +++ b/include/linux/irqflags.h @@ -69,6 +69,17 @@ do { \ current->irq_config =3D 0; \ } while (0) =20 +# define lockdep_irq_work_enter(__work) \ + do { \ + if (!(atomic_read(&__work->flags) & IRQ_WORK_HARD_IRQ))\ + current->irq_config =3D 1; \ + } while (0) +# define lockdep_irq_work_exit(__work) \ + do { \ + if (!(atomic_read(&__work->flags) & IRQ_WORK_HARD_IRQ))\ + current->irq_config =3D 0; \ + } while (0) + #else # define trace_hardirqs_on() do { } while (0) # define trace_hardirqs_off() do { } while (0) @@ -83,6 +94,8 @@ do { \ # define lockdep_softirq_exit() do { } while (0) # define lockdep_hrtimer_enter(__hrtimer) do { } while (0) # define lockdep_hrtimer_exit(__hrtimer) do { } while (0) +# define lockdep_irq_work_enter(__work) do { } while (0) +# define lockdep_irq_work_exit(__work) do { } while (0) #endif =20 #if defined(CONFIG_IRQSOFF_TRACER) || \ diff --git a/kernel/irq_work.c b/kernel/irq_work.c index 828cc30774bc4..48b5d1b6af4d3 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -153,7 +153,9 @@ static void irq_work_run_list(struct llist_head *list) */ flags =3D atomic_fetch_andnot(IRQ_WORK_PENDING, &work->flags); =20 + lockdep_irq_work_enter(work); work->func(work); + lockdep_irq_work_exit(work); /* * Clear the BUSY bit and return to the free state if * no-one else claimed it meanwhile. diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index d91c9156fab2e..5066d1dd30777 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1113,6 +1113,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *= rdp) !rdp->rcu_iw_pending && rdp->rcu_iw_gp_seq !=3D rnp->gp_seq && (rnp->ffmask & rdp->grpmask)) { init_irq_work(&rdp->rcu_iw, rcu_iw_handler); + atomic_set(&rdp->rcu_iw.flags, IRQ_WORK_HARD_IRQ); rdp->rcu_iw_pending =3D true; rdp->rcu_iw_gp_seq =3D rnp->gp_seq; irq_work_queue_on(&rdp->rcu_iw, rdp->cpu); diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 4be756b88a48e..3e2dc9b8858c7 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -245,6 +245,7 @@ static void nohz_full_kick_func(struct irq_work *work) =20 static DEFINE_PER_CPU(struct irq_work, nohz_full_kick_work) =3D { .func =3D nohz_full_kick_func, + .flags =3D ATOMIC_INIT(IRQ_WORK_HARD_IRQ), }; =20 /* --=20 2.25.1