From patchwork Wed Jun 8 14:27:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 580509 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 4A9EBC433EF for ; Wed, 8 Jun 2022 14:52:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243283AbiFHOwD (ORCPT ); Wed, 8 Jun 2022 10:52:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242375AbiFHOrI (ORCPT ); Wed, 8 Jun 2022 10:47:08 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91CAA254EDA; Wed, 8 Jun 2022 07:46:54 -0700 (PDT) DKIM-Signature: v=1; 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Wed, 8 Jun 2022 16:46:22 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 71E0D20C10EAA; Wed, 8 Jun 2022 16:46:18 +0200 (CEST) Message-ID: <20220608144516.808451191@infradead.org> User-Agent: quilt/0.66 Date: Wed, 08 Jun 2022 16:27:37 +0200 From: Peter Zijlstra To: peterz@infradead.org Cc: rth@twiddle.net, ink@jurassic.park.msu.ru, mattst88@gmail.com, vgupta@kernel.org, linux@armlinux.org.uk, ulli.kroll@googlemail.com, linus.walleij@linaro.org, shawnguo@kernel.org, Sascha Hauer , kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, tony@atomide.com, khilman@kernel.org, catalin.marinas@arm.com, will@kernel.org, guoren@kernel.org, bcain@quicinc.com, chenhuacai@kernel.org, kernel@xen0n.name, geert@linux-m68k.org, sammy@sammy.net, monstr@monstr.eu, tsbogend@alpha.franken.de, dinguyen@kernel.org, jonas@southpole.se, stefan.kristiansson@saunalahti.fi, shorne@gmail.com, James.Bottomley@HansenPartnership.com, deller@gmx.de, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, ysato@users.sourceforge.jp, dalias@libc.org, davem@davemloft.net, richard@nod.at, anton.ivanov@cambridgegreys.com, johannes@sipsolutions.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, jgross@suse.com, srivatsa@csail.mit.edu, amakhalov@vmware.com, pv-drivers@vmware.com, boris.ostrovsky@oracle.com, chris@zankel.net, jcmvbkbc@gmail.com, rafael@kernel.org, lenb@kernel.org, pavel@ucw.cz, gregkh@linuxfoundation.org, mturquette@baylibre.com, sboyd@kernel.org, daniel.lezcano@linaro.org, lpieralisi@kernel.org, sudeep.holla@arm.com, agross@kernel.org, bjorn.andersson@linaro.org, anup@brainfault.org, thierry.reding@gmail.com, jonathanh@nvidia.com, jacob.jun.pan@linux.intel.com, Arnd Bergmann , yury.norov@gmail.com, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, rostedt@goodmis.org, pmladek@suse.com, senozhatsky@chromium.org, john.ogness@linutronix.de, paulmck@kernel.org, frederic@kernel.org, quic_neeraju@quicinc.com, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, joel@joelfernandes.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, jpoimboe@kernel.org, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-perf-users@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, linux-xtensa@linux-xtensa.org, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-clk@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arch@vger.kernel.org, rcu@vger.kernel.org Subject: [PATCH 14/36] cpuidle: Fix rcu_idle_*() usage References: <20220608142723.103523089@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The whole disable-RCU, enable-IRQS dance is very intricate since changing IRQ state is traced, which depends on RCU. Add two helpers for the cpuidle case that mirror the entry code. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Gautham R. Shenoy --- arch/arm/mach-imx/cpuidle-imx6q.c | 4 +-- arch/arm/mach-imx/cpuidle-imx6sx.c | 4 +-- arch/arm/mach-omap2/cpuidle34xx.c | 4 +-- arch/arm/mach-omap2/cpuidle44xx.c | 8 +++--- drivers/acpi/processor_idle.c | 18 ++++++++------ drivers/cpuidle/cpuidle-big_little.c | 4 +-- drivers/cpuidle/cpuidle-mvebu-v7.c | 4 +-- drivers/cpuidle/cpuidle-psci.c | 4 +-- drivers/cpuidle/cpuidle-riscv-sbi.c | 4 +-- drivers/cpuidle/cpuidle-tegra.c | 8 +++--- drivers/cpuidle/cpuidle.c | 11 ++++---- include/linux/cpuidle.h | 37 +++++++++++++++++++++++++--- kernel/sched/idle.c | 45 ++++++++++------------------------- kernel/time/tick-broadcast.c | 6 +++- 14 files changed, 90 insertions(+), 71 deletions(-) --- a/arch/arm/mach-imx/cpuidle-imx6q.c +++ b/arch/arm/mach-imx/cpuidle-imx6q.c @@ -24,9 +24,9 @@ static int imx6q_enter_wait(struct cpuid imx6_set_lpm(WAIT_UNCLOCKED); raw_spin_unlock(&cpuidle_lock); - rcu_idle_enter(); + cpuidle_rcu_enter(); cpu_do_idle(); - rcu_idle_exit(); + cpuidle_rcu_exit(); raw_spin_lock(&cpuidle_lock); if (num_idle_cpus-- == num_online_cpus()) --- a/arch/arm/mach-imx/cpuidle-imx6sx.c +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c @@ -47,9 +47,9 @@ static int imx6sx_enter_wait(struct cpui cpu_pm_enter(); cpu_cluster_pm_enter(); - rcu_idle_enter(); + cpuidle_rcu_enter(); cpu_suspend(0, imx6sx_idle_finish); - rcu_idle_exit(); + cpuidle_rcu_exit(); cpu_cluster_pm_exit(); cpu_pm_exit(); --- a/arch/arm/mach-omap2/cpuidle34xx.c +++ b/arch/arm/mach-omap2/cpuidle34xx.c @@ -133,9 +133,9 @@ static int omap3_enter_idle(struct cpuid } /* Execute ARM wfi */ - rcu_idle_enter(); + cpuidle_rcu_enter(); omap_sram_idle(); - rcu_idle_exit(); + cpuidle_rcu_exit(); /* * Call idle CPU PM enter notifier chain to restore --- a/arch/arm/mach-omap2/cpuidle44xx.c +++ b/arch/arm/mach-omap2/cpuidle44xx.c @@ -105,9 +105,9 @@ static int omap_enter_idle_smp(struct cp } raw_spin_unlock_irqrestore(&mpu_lock, flag); - rcu_idle_enter(); + cpuidle_rcu_enter(); omap4_enter_lowpower(dev->cpu, cx->cpu_state); - rcu_idle_exit(); + cpuidle_rcu_exit(); raw_spin_lock_irqsave(&mpu_lock, flag); if (cx->mpu_state_vote == num_online_cpus()) @@ -186,10 +186,10 @@ static int omap_enter_idle_coupled(struc } } - rcu_idle_enter(); + cpuidle_rcu_enter(); omap4_enter_lowpower(dev->cpu, cx->cpu_state); cpu_done[dev->cpu] = true; - rcu_idle_exit(); + cpuidle_rcu_exit(); /* Wakeup CPU1 only if it is not offlined */ if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) { --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -607,7 +607,7 @@ static DEFINE_RAW_SPINLOCK(c3_lock); * @cx: Target state context * @index: index of target state */ -static int acpi_idle_enter_bm(struct cpuidle_driver *drv, +static noinstr int acpi_idle_enter_bm(struct cpuidle_driver *drv, struct acpi_processor *pr, struct acpi_processor_cx *cx, int index) @@ -626,6 +626,8 @@ static int acpi_idle_enter_bm(struct cpu */ bool dis_bm = pr->flags.bm_control; + instrumentation_begin(); + /* If we can skip BM, demote to a safe state. */ if (!cx->bm_sts_skip && acpi_idle_bm_check()) { dis_bm = false; @@ -647,11 +649,11 @@ static int acpi_idle_enter_bm(struct cpu raw_spin_unlock(&c3_lock); } - rcu_idle_enter(); + cpuidle_rcu_enter(); acpi_idle_do_entry(cx); - rcu_idle_exit(); + cpuidle_rcu_exit(); /* Re-enable bus master arbitration */ if (dis_bm) { @@ -661,11 +663,13 @@ static int acpi_idle_enter_bm(struct cpu raw_spin_unlock(&c3_lock); } + instrumentation_end(); + return index; } -static int acpi_idle_enter(struct cpuidle_device *dev, - struct cpuidle_driver *drv, int index) +static noinstr int acpi_idle_enter(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) { struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); struct acpi_processor *pr; @@ -693,8 +697,8 @@ static int acpi_idle_enter(struct cpuidl return index; } -static int acpi_idle_enter_s2idle(struct cpuidle_device *dev, - struct cpuidle_driver *drv, int index) +static noinstr int acpi_idle_enter_s2idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, int index) { struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu); --- a/drivers/cpuidle/cpuidle-big_little.c +++ b/drivers/cpuidle/cpuidle-big_little.c @@ -126,13 +126,13 @@ static int bl_enter_powerdown(struct cpu struct cpuidle_driver *drv, int idx) { cpu_pm_enter(); - rcu_idle_enter(); + cpuidle_rcu_enter(); cpu_suspend(0, bl_powerdown_finisher); /* signals the MCPM core that CPU is out of low power state */ mcpm_cpu_powered_up(); - rcu_idle_exit(); + cpuidle_rcu_exit(); cpu_pm_exit(); --- a/drivers/cpuidle/cpuidle-mvebu-v7.c +++ b/drivers/cpuidle/cpuidle-mvebu-v7.c @@ -36,9 +36,9 @@ static int mvebu_v7_enter_idle(struct cp if (drv->states[index].flags & MVEBU_V7_FLAG_DEEP_IDLE) deepidle = true; - rcu_idle_enter(); + cpuidle_rcu_enter(); ret = mvebu_v7_cpu_suspend(deepidle); - rcu_idle_exit(); + cpuidle_rcu_exit(); cpu_pm_exit(); --- a/drivers/cpuidle/cpuidle-psci.c +++ b/drivers/cpuidle/cpuidle-psci.c @@ -74,7 +74,7 @@ static int __psci_enter_domain_idle_stat else pm_runtime_put_sync_suspend(pd_dev); - rcu_idle_enter(); + cpuidle_rcu_enter(); state = psci_get_domain_state(); if (!state) @@ -82,7 +82,7 @@ static int __psci_enter_domain_idle_stat ret = psci_cpu_suspend_enter(state) ? -1 : idx; - rcu_idle_exit(); + cpuidle_rcu_exit(); if (s2idle) dev_pm_genpd_resume(pd_dev); --- a/drivers/cpuidle/cpuidle-riscv-sbi.c +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c @@ -121,7 +121,7 @@ static int __sbi_enter_domain_idle_state else pm_runtime_put_sync_suspend(pd_dev); - rcu_idle_enter(); + cpuidle_rcu_enter(); if (sbi_is_domain_state_available()) state = sbi_get_domain_state(); @@ -130,7 +130,7 @@ static int __sbi_enter_domain_idle_state ret = sbi_suspend(state) ? -1 : idx; - rcu_idle_exit(); + cpuidle_rcu_exit(); if (s2idle) dev_pm_genpd_resume(pd_dev); --- a/drivers/cpuidle/cpuidle-tegra.c +++ b/drivers/cpuidle/cpuidle-tegra.c @@ -183,7 +183,7 @@ static int tegra_cpuidle_state_enter(str tegra_pm_set_cpu_in_lp2(); cpu_pm_enter(); - rcu_idle_enter(); + cpuidle_rcu_enter(); switch (index) { case TEGRA_C7: @@ -199,7 +199,7 @@ static int tegra_cpuidle_state_enter(str break; } - rcu_idle_exit(); + cpuidle_rcu_exit(); cpu_pm_exit(); tegra_pm_clear_cpu_in_lp2(); @@ -240,10 +240,10 @@ static int tegra_cpuidle_enter(struct cp if (index == TEGRA_C1) { if (do_rcu) - rcu_idle_enter(); + cpuidle_rcu_enter(); ret = arm_cpuidle_simple_enter(dev, drv, index); if (do_rcu) - rcu_idle_exit(); + cpuidle_rcu_exit(); } else ret = tegra_cpuidle_state_enter(dev, index, cpu); --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -150,12 +151,12 @@ static void enter_s2idle_proper(struct c */ stop_critical_timings(); if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) - rcu_idle_enter(); + cpuidle_rcu_enter(); target_state->enter_s2idle(dev, drv, index); if (WARN_ON_ONCE(!irqs_disabled())) - local_irq_disable(); + raw_local_irq_disable(); if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) - rcu_idle_exit(); + cpuidle_rcu_exit(); tick_unfreeze(); start_critical_timings(); @@ -233,14 +234,14 @@ int cpuidle_enter_state(struct cpuidle_d stop_critical_timings(); if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) - rcu_idle_enter(); + cpuidle_rcu_enter(); entered_state = target_state->enter(dev, drv, index); if (WARN_ONCE(!irqs_disabled(), "%ps leaked IRQ state", target_state->enter)) raw_local_irq_disable(); if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) - rcu_idle_exit(); + cpuidle_rcu_exit(); start_critical_timings(); sched_clock_idle_wakeup_event(); --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -115,6 +115,35 @@ struct cpuidle_device { DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); DECLARE_PER_CPU(struct cpuidle_device, cpuidle_dev); +static __always_inline void cpuidle_rcu_enter(void) +{ + lockdep_assert_irqs_disabled(); + /* + * Idle is allowed to (temporary) enable IRQs. It + * will return with IRQs disabled. + * + * Trace IRQs enable here, then switch off RCU, and have + * arch_cpu_idle() use raw_local_irq_enable(). Note that + * rcu_idle_enter() relies on lockdep IRQ state, so switch that + * last -- this is very similar to the entry code. + */ + trace_hardirqs_on_prepare(); + lockdep_hardirqs_on_prepare(); + instrumentation_end(); + rcu_idle_enter(); + lockdep_hardirqs_on(_THIS_IP_); +} + +static __always_inline void cpuidle_rcu_exit(void) +{ + /* + * Carefully undo the above. + */ + lockdep_hardirqs_off(_THIS_IP_); + rcu_idle_exit(); + instrumentation_begin(); +} + /**************************** * CPUIDLE DRIVER INTERFACE * ****************************/ @@ -282,18 +311,18 @@ extern s64 cpuidle_governor_latency_req( int __ret = 0; \ \ if (!idx) { \ - rcu_idle_enter(); \ + cpuidle_rcu_enter(); \ cpu_do_idle(); \ - rcu_idle_exit(); \ + cpuidle_rcu_exit(); \ return idx; \ } \ \ if (!is_retention) \ __ret = cpu_pm_enter(); \ if (!__ret) { \ - rcu_idle_enter(); \ + cpuidle_rcu_enter(); \ __ret = low_level_idle_enter(state); \ - rcu_idle_exit(); \ + cpuidle_rcu_exit(); \ if (!is_retention) \ cpu_pm_exit(); \ } \ --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -51,18 +51,22 @@ __setup("hlt", cpu_idle_nopoll_setup); static noinline int __cpuidle cpu_idle_poll(void) { + instrumentation_begin(); trace_cpu_idle(0, smp_processor_id()); stop_critical_timings(); - rcu_idle_enter(); - local_irq_enable(); + cpuidle_rcu_enter(); + raw_local_irq_enable(); while (!tif_need_resched() && (cpu_idle_force_poll || tick_check_broadcast_expired())) cpu_relax(); + raw_local_irq_disable(); - rcu_idle_exit(); + cpuidle_rcu_exit(); start_critical_timings(); trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id()); + local_irq_enable(); + instrumentation_end(); return 1; } @@ -85,44 +89,21 @@ void __weak arch_cpu_idle(void) */ void __cpuidle default_idle_call(void) { - if (current_clr_polling_and_test()) { - local_irq_enable(); - } else { - + instrumentation_begin(); + if (!current_clr_polling_and_test()) { trace_cpu_idle(1, smp_processor_id()); stop_critical_timings(); - /* - * arch_cpu_idle() is supposed to enable IRQs, however - * we can't do that because of RCU and tracing. - * - * Trace IRQs enable here, then switch off RCU, and have - * arch_cpu_idle() use raw_local_irq_enable(). Note that - * rcu_idle_enter() relies on lockdep IRQ state, so switch that - * last -- this is very similar to the entry code. - */ - trace_hardirqs_on_prepare(); - lockdep_hardirqs_on_prepare(); - rcu_idle_enter(); - lockdep_hardirqs_on(_THIS_IP_); - + cpuidle_rcu_enter(); arch_cpu_idle(); - - /* - * OK, so IRQs are enabled here, but RCU needs them disabled to - * turn itself back on.. funny thing is that disabling IRQs - * will cause tracing, which needs RCU. Jump through hoops to - * make it 'work'. - */ raw_local_irq_disable(); - lockdep_hardirqs_off(_THIS_IP_); - rcu_idle_exit(); - lockdep_hardirqs_on(_THIS_IP_); - raw_local_irq_enable(); + cpuidle_rcu_exit(); start_critical_timings(); trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id()); } + local_irq_enable(); + instrumentation_end(); } static int call_cpuidle_s2idle(struct cpuidle_driver *drv, --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -622,9 +622,13 @@ struct cpumask *tick_get_broadcast_onesh * to avoid a deep idle transition as we are about to get the * broadcast IPI right away. */ -int tick_check_broadcast_expired(void) +noinstr int tick_check_broadcast_expired(void) { +#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H + return arch_test_bit(smp_processor_id(), cpumask_bits(tick_broadcast_force_mask)); +#else return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask); +#endif } /*