From: Frederic Weisbecker <frederic@kernel.org>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>,
Marco Crivellari <marco.crivellari@suse.com>,
Peter Zijlstra <peterz@infradead.org>,
Phil Auld <pauld@redhat.com>, Thomas Gleixner <tglx@kernel.org>,
Waiman Long <longman@redhat.com>
Subject: [RFC PATCH 06/49] cpu: Move CPUHP_AP_IRQ_ARMADA_XP_STARTING..CPUHP_AP_IRQ_GIC_STARTING range post stop_machine()
Date: Mon, 19 Oct 2026 15:08:13 +0200 [thread overview]
Message-ID: <20261019130856.49711-7-frederic@kernel.org> (raw)
In-Reply-To: <20261019130856.49711-1-frederic@kernel.org>
Between CPUHP_TEARDOWN_CPU and CPUHP_AP_OFFLINE, stop_machine executes
all the teardown callbacks while stopping all CPUs in the system. This
doesn't mix-up well with running RT or isolated tasks.
In order to transition smoothly from global stop_machine to finer
grained synchronization between teardown callbacks and the other CPUs,
a new stop machine post function has been introduced to be executed
after the main one with IRQs still disabled while other CPUs can exit
stop_machine().
Here none of these states have teardown callbacks.
Move these teardown callbacks to post stop_machine() accordingly.
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
---
kernel/cpu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 68eb8de820d5..293dbb73d940 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -1275,7 +1275,7 @@ void clear_tasks_mm_cpumask(int cpu)
static int take_cpu_down(void *_param)
{
struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state);
- enum cpuhp_state target = max((int)st->target, CPUHP_AP_CPU_PM_STARTING);
+ enum cpuhp_state target = max((int)st->target, CPUHP_AP_IRQ_ARMADA_XP_STARTING);
int err, cpu = smp_processor_id();
/* Ensure this CPU doesn't handle any more interrupts. */
@@ -1303,7 +1303,7 @@ static int take_cpu_down_post(void *_param)
enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE);
int cpu = smp_processor_id();
- WARN_ON(st->state != CPUHP_AP_CPU_PM_STARTING);
+ WARN_ON(st->state != CPUHP_AP_IRQ_ARMADA_XP_STARTING);
/*
* Invoke the former CPU_DYING callbacks. DYING must not fail!
*/
--
2.53.0
next prev parent reply other threads:[~2026-10-19 13:09 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-19 13:08 [RFC PATCH 00/49] cpu/hotplug: Remove cpu_down() global stop_machine() except for CPUHP_TEARDOWN_CPU itself Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 01/49] stop_machine: Add post function to execute while other CPUs can exit Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 02/49] x86/cpu/cacheinfo: Move CPUHP_AP_CACHECTRL_STARTING to post stop machine Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 03/49] sched: Move CPUHP_AP_SCHED_STARTING to post stop_machine() Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 04/49] rcu: Move CPUHP_AP_RCUTREE_DYING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 05/49] cpuidle: Move CPUHP_AP_CPU_PM_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` Frederic Weisbecker [this message]
2026-10-19 13:08 ` [RFC PATCH 07/49] irqchip/bcm2836: Move CPUHP_AP_IRQ_BCM2836_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 08/49] cpu: Move [CPUHP_AP_IRQ_EIOINTC_STARTING..CPUHP_AP_IRQ_MIPS_GIC_STARTING] range " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 09/49] irqchip/loongarch-avec: Move CPUHP_AP_IRQ_AVECINTC_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 10/49] irqchip/sifive-plic: Move CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 11/49] irqchip/aslint-sswi: Move CPUHP_AP_IRQ_ACLINT_SSWI_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 12/49] irqchip/irq-riscv-imsic-early: Move CPUHP_AP_IRQ_RISCV_IMSIC_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 13/49] cpu: Move [CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING..CPUHP_AP_IRQ_RISCV_SBI_IPI_STARTING] range " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 14/49] perf/x86: Move CPUHP_AP_PERF_X86_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 15/49] perf/amd/ibs: Move CPUHP_AP_PERF_X86_AMD_IBS_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 16/49] cpu: Move CPUHP_AP_PERF_XTENSA_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 17/49] ARM: vfp: Move CPUHP_AP_ARM_VFP_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 18/49] cpu: Move [CPUHP_AP_PERF_ARM_ACPI_STARTING..CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING] range " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 19/49] perf/arm_pmu: Move CPUHP_AP_PERF_ARM_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 20/49] perf: RISC-V: Move CPUHP_AP_PERF_RISCV_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 21/49] ARM: l2c: Move CPUHP_AP_ARM_L2X0_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 22/49] clocksource/drivers/exynos_mct: Move CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 23/49] clocksource/drivers/arm_arch_timer: Move CPUHP_AP_ARM_ARCH_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 24/49] clocksource/drivers/arm_arch_timer: Move CPUHP_AP_ARM_ARCH_TIMER_EVTSTRM_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 25/49] clocksource/drivers/arm_global_timer: Move CPUHP_AP_ARM_GLOBAL_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 26/49] clocksource/drivers/jcore: Move CPUHP_AP_JCORE_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 27/49] ARM: smp_twd: Move CPUHP_AP_ARM_TWD_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 28/49] clocksource/drivers/qcom: Move CPUHP_AP_QCOM_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 29/49] clocksource/drivers/timer-tegra: Move CPUHP_AP_TEGRA_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 30/49] clocksource/drivers/armada: Move CPUHP_AP_ARMADA_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 31/49] LoongArch: Move CPUHP_AP_LOONGARCH_ARCH_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 32/49] clocksource/drivers/mips-gic-timer: Move CPUHP_AP_MIPS_GIC_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 33/49] clocksource/drivers/arc_timer: Move CPUHP_AP_ARC_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 34/49] clocksource/drivers/rtl-otto: Move CPUHP_AP_REALTEK_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 35/49] clocksource/drivers/timer-riscv: Move CPUHP_AP_RISCV_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 36/49] clocksource: clint: Move CPUHP_AP_CLINT_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 37/49] clocksource/drivers/c-sky: Move CPUHP_AP_CSKY_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 38/49] clocksource/drivers/timer-ti-dm: Move CPUHP_AP_TI_GP_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 39/49] clocksource: hyper-v: Move CPUHP_AP_HYPERV_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 40/49] clocksource/dummy_timer: Move CPUHP_AP_DUMMY_TIMER_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 41/49] ARM: xen: Move CPUHP_AP_ARM_XEN_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 42/49] ARM: xen: Move CPUHP_AP_ARM_XEN_RUNSTATE_STARTING and CPUHP_AP_ARM64_ISNDEP_STARTING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 43/49] smp: Move CPUHP_AP_SMPCFD_DYING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 44/49] hrtimer: Move CPUHP_AP_HRTIMERS_DYING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 45/49] irq_work: Introduce irq_work_kick_cpu() Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 46/49] tick-sched: Convert ad-hoc implementation of irq_work_kick_cpu() Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 47/49] tick: Move CPUHP_AP_TICK_DYING post stop_machine() Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 48/49] x86/boot/tboot: Move CPUHP_AP_X86_TBOOT_DYING " Frederic Weisbecker
2026-10-19 13:08 ` [RFC PATCH 49/49] ARM: mm: Move CPUHP_AP_ARM_CACHE_B15_RAC_DYING " Frederic Weisbecker
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