linux-stable/include/linux/cpuhotplug.h
Thomas Gleixner 1cf12e08bc sched/hotplug: Consolidate task migration on CPU unplug
With the new mechanism which kicks tasks off the outgoing CPU at the end of
schedule() the situation on an outgoing CPU right before the stopper thread
brings it down completely is:

 - All user tasks and all unbound kernel threads have either been migrated
   away or are not running and the next wakeup will move them to a online CPU.

 - All per CPU kernel threads, except cpu hotplug thread and the stopper
   thread have either been unbound or parked by the responsible CPU hotplug
   callback.

That means that at the last step before the stopper thread is invoked the
cpu hotplug thread is the last legitimate running task on the outgoing
CPU.

Add a final wait step right before the stopper thread is kicked which
ensures that any still running tasks on the way to park or on the way to
kick themself of the CPU are either sleeping or gone.

This allows to remove the migrate_tasks() crutch in sched_cpu_dying(). If
sched_cpu_dying() detects that there is still another running task aside of
the stopper thread then it will explode with the appropriate fireworks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.547163969@infradead.org
2020-11-10 18:38:58 +01:00

413 lines
13 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __CPUHOTPLUG_H
#define __CPUHOTPLUG_H
#include <linux/types.h>
/*
* CPU-up CPU-down
*
* BP AP BP AP
*
* OFFLINE OFFLINE
* | ^
* v |
* BRINGUP_CPU->AP_OFFLINE BRINGUP_CPU <- AP_IDLE_DEAD (idle thread/play_dead)
* | AP_OFFLINE
* v (IRQ-off) ,---------------^
* AP_ONLNE | (stop_machine)
* | TEARDOWN_CPU <- AP_ONLINE_IDLE
* | ^
* v |
* AP_ACTIVE AP_ACTIVE
*/
enum cpuhp_state {
CPUHP_INVALID = -1,
CPUHP_OFFLINE = 0,
CPUHP_CREATE_THREADS,
CPUHP_PERF_PREPARE,
CPUHP_PERF_X86_PREPARE,
CPUHP_PERF_X86_AMD_UNCORE_PREP,
CPUHP_PERF_POWER,
CPUHP_PERF_SUPERH,
CPUHP_X86_HPET_DEAD,
CPUHP_X86_APB_DEAD,
CPUHP_X86_MCE_DEAD,
CPUHP_VIRT_NET_DEAD,
CPUHP_SLUB_DEAD,
CPUHP_DEBUG_OBJ_DEAD,
CPUHP_MM_WRITEBACK_DEAD,
CPUHP_MM_VMSTAT_DEAD,
CPUHP_SOFTIRQ_DEAD,
CPUHP_NET_MVNETA_DEAD,
CPUHP_CPUIDLE_DEAD,
CPUHP_ARM64_FPSIMD_DEAD,
CPUHP_ARM_OMAP_WAKE_DEAD,
CPUHP_IRQ_POLL_DEAD,
CPUHP_BLOCK_SOFTIRQ_DEAD,
CPUHP_ACPI_CPUDRV_DEAD,
CPUHP_S390_PFAULT_DEAD,
CPUHP_BLK_MQ_DEAD,
CPUHP_FS_BUFF_DEAD,
CPUHP_PRINTK_DEAD,
CPUHP_MM_MEMCQ_DEAD,
CPUHP_PERCPU_CNT_DEAD,
CPUHP_RADIX_DEAD,
CPUHP_PAGE_ALLOC_DEAD,
CPUHP_NET_DEV_DEAD,
CPUHP_PCI_XGENE_DEAD,
CPUHP_IOMMU_INTEL_DEAD,
CPUHP_LUSTRE_CFS_DEAD,
CPUHP_AP_ARM_CACHE_B15_RAC_DEAD,
CPUHP_PADATA_DEAD,
CPUHP_WORKQUEUE_PREP,
CPUHP_POWER_NUMA_PREPARE,
CPUHP_HRTIMERS_PREPARE,
CPUHP_PROFILE_PREPARE,
CPUHP_X2APIC_PREPARE,
CPUHP_SMPCFD_PREPARE,
CPUHP_RELAY_PREPARE,
CPUHP_SLAB_PREPARE,
CPUHP_MD_RAID5_PREPARE,
CPUHP_RCUTREE_PREP,
CPUHP_CPUIDLE_COUPLED_PREPARE,
CPUHP_POWERPC_PMAC_PREPARE,
CPUHP_POWERPC_MMU_CTX_PREPARE,
CPUHP_XEN_PREPARE,
CPUHP_XEN_EVTCHN_PREPARE,
CPUHP_ARM_SHMOBILE_SCU_PREPARE,
CPUHP_SH_SH3X_PREPARE,
CPUHP_NET_FLOW_PREPARE,
CPUHP_TOPOLOGY_PREPARE,
CPUHP_NET_IUCV_PREPARE,
CPUHP_ARM_BL_PREPARE,
CPUHP_TRACE_RB_PREPARE,
CPUHP_MM_ZS_PREPARE,
CPUHP_MM_ZSWP_MEM_PREPARE,
CPUHP_MM_ZSWP_POOL_PREPARE,
CPUHP_KVM_PPC_BOOK3S_PREPARE,
CPUHP_ZCOMP_PREPARE,
CPUHP_TIMERS_PREPARE,
CPUHP_MIPS_SOC_PREPARE,
CPUHP_BP_PREPARE_DYN,
CPUHP_BP_PREPARE_DYN_END = CPUHP_BP_PREPARE_DYN + 20,
CPUHP_BRINGUP_CPU,
CPUHP_AP_IDLE_DEAD,
CPUHP_AP_OFFLINE,
CPUHP_AP_SCHED_STARTING,
CPUHP_AP_RCUTREE_DYING,
CPUHP_AP_CPU_PM_STARTING,
CPUHP_AP_IRQ_GIC_STARTING,
CPUHP_AP_IRQ_HIP04_STARTING,
CPUHP_AP_IRQ_ARMADA_XP_STARTING,
CPUHP_AP_IRQ_BCM2836_STARTING,
CPUHP_AP_IRQ_MIPS_GIC_STARTING,
CPUHP_AP_IRQ_RISCV_STARTING,
CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
CPUHP_AP_ARM_MVEBU_COHERENCY,
CPUHP_AP_MICROCODE_LOADER,
CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
CPUHP_AP_PERF_X86_STARTING,
CPUHP_AP_PERF_X86_AMD_IBS_STARTING,
CPUHP_AP_PERF_X86_CQM_STARTING,
CPUHP_AP_PERF_X86_CSTATE_STARTING,
CPUHP_AP_PERF_XTENSA_STARTING,
CPUHP_AP_MIPS_OP_LOONGSON3_STARTING,
CPUHP_AP_ARM_SDEI_STARTING,
CPUHP_AP_ARM_VFP_STARTING,
CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING,
CPUHP_AP_PERF_ARM_HW_BREAKPOINT_STARTING,
CPUHP_AP_PERF_ARM_ACPI_STARTING,
CPUHP_AP_PERF_ARM_STARTING,
CPUHP_AP_ARM_L2X0_STARTING,
CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
CPUHP_AP_ARM_ARCH_TIMER_STARTING,
CPUHP_AP_ARM_GLOBAL_TIMER_STARTING,
CPUHP_AP_JCORE_TIMER_STARTING,
CPUHP_AP_ARM_TWD_STARTING,
CPUHP_AP_QCOM_TIMER_STARTING,
CPUHP_AP_TEGRA_TIMER_STARTING,
CPUHP_AP_ARMADA_TIMER_STARTING,
CPUHP_AP_MARCO_TIMER_STARTING,
CPUHP_AP_MIPS_GIC_TIMER_STARTING,
CPUHP_AP_ARC_TIMER_STARTING,
CPUHP_AP_RISCV_TIMER_STARTING,
CPUHP_AP_CLINT_TIMER_STARTING,
CPUHP_AP_CSKY_TIMER_STARTING,
CPUHP_AP_HYPERV_TIMER_STARTING,
CPUHP_AP_KVM_STARTING,
CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
CPUHP_AP_KVM_ARM_VGIC_STARTING,
CPUHP_AP_KVM_ARM_TIMER_STARTING,
/* Must be the last timer callback */
CPUHP_AP_DUMMY_TIMER_STARTING,
CPUHP_AP_ARM_XEN_STARTING,
CPUHP_AP_ARM_CORESIGHT_STARTING,
CPUHP_AP_ARM_CORESIGHT_CTI_STARTING,
CPUHP_AP_ARM64_ISNDEP_STARTING,
CPUHP_AP_SMPCFD_DYING,
CPUHP_AP_X86_TBOOT_DYING,
CPUHP_AP_ARM_CACHE_B15_RAC_DYING,
CPUHP_AP_ONLINE,
CPUHP_TEARDOWN_CPU,
CPUHP_AP_ONLINE_IDLE,
CPUHP_AP_SCHED_WAIT_EMPTY,
CPUHP_AP_SMPBOOT_THREADS,
CPUHP_AP_X86_VDSO_VMA_ONLINE,
CPUHP_AP_IRQ_AFFINITY_ONLINE,
CPUHP_AP_BLK_MQ_ONLINE,
CPUHP_AP_ARM_MVEBU_SYNC_CLOCKS,
CPUHP_AP_X86_INTEL_EPB_ONLINE,
CPUHP_AP_PERF_ONLINE,
CPUHP_AP_PERF_X86_ONLINE,
CPUHP_AP_PERF_X86_UNCORE_ONLINE,
CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
CPUHP_AP_PERF_X86_AMD_POWER_ONLINE,
CPUHP_AP_PERF_X86_RAPL_ONLINE,
CPUHP_AP_PERF_X86_CQM_ONLINE,
CPUHP_AP_PERF_X86_CSTATE_ONLINE,
CPUHP_AP_PERF_S390_CF_ONLINE,
CPUHP_AP_PERF_S390_SF_ONLINE,
CPUHP_AP_PERF_ARM_CCI_ONLINE,
CPUHP_AP_PERF_ARM_CCN_ONLINE,
CPUHP_AP_PERF_ARM_HISI_DDRC_ONLINE,
CPUHP_AP_PERF_ARM_HISI_HHA_ONLINE,
CPUHP_AP_PERF_ARM_HISI_L3_ONLINE,
CPUHP_AP_PERF_ARM_L2X0_ONLINE,
CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
CPUHP_AP_PERF_ARM_QCOM_L3_ONLINE,
CPUHP_AP_PERF_ARM_APM_XGENE_ONLINE,
CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE,
CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE,
CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
CPUHP_AP_PERF_POWERPC_TRACE_IMC_ONLINE,
CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE,
CPUHP_AP_PERF_POWERPC_HV_GPCI_ONLINE,
CPUHP_AP_WATCHDOG_ONLINE,
CPUHP_AP_WORKQUEUE_ONLINE,
CPUHP_AP_RCUTREE_ONLINE,
CPUHP_AP_BASE_CACHEINFO_ONLINE,
CPUHP_AP_ONLINE_DYN,
CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30,
CPUHP_AP_X86_HPET_ONLINE,
CPUHP_AP_X86_KVM_CLK_ONLINE,
CPUHP_AP_ACTIVE,
CPUHP_ONLINE,
};
int __cpuhp_setup_state(enum cpuhp_state state, const char *name, bool invoke,
int (*startup)(unsigned int cpu),
int (*teardown)(unsigned int cpu), bool multi_instance);
int __cpuhp_setup_state_cpuslocked(enum cpuhp_state state, const char *name,
bool invoke,
int (*startup)(unsigned int cpu),
int (*teardown)(unsigned int cpu),
bool multi_instance);
/**
* cpuhp_setup_state - Setup hotplug state callbacks with calling the callbacks
* @state: The state for which the calls are installed
* @name: Name of the callback (will be used in debug output)
* @startup: startup callback function
* @teardown: teardown callback function
*
* Installs the callback functions and invokes the startup callback on
* the present cpus which have already reached the @state.
*/
static inline int cpuhp_setup_state(enum cpuhp_state state,
const char *name,
int (*startup)(unsigned int cpu),
int (*teardown)(unsigned int cpu))
{
return __cpuhp_setup_state(state, name, true, startup, teardown, false);
}
static inline int cpuhp_setup_state_cpuslocked(enum cpuhp_state state,
const char *name,
int (*startup)(unsigned int cpu),
int (*teardown)(unsigned int cpu))
{
return __cpuhp_setup_state_cpuslocked(state, name, true, startup,
teardown, false);
}
/**
* cpuhp_setup_state_nocalls - Setup hotplug state callbacks without calling the
* callbacks
* @state: The state for which the calls are installed
* @name: Name of the callback.
* @startup: startup callback function
* @teardown: teardown callback function
*
* Same as @cpuhp_setup_state except that no calls are executed are invoked
* during installation of this callback. NOP if SMP=n or HOTPLUG_CPU=n.
*/
static inline int cpuhp_setup_state_nocalls(enum cpuhp_state state,
const char *name,
int (*startup)(unsigned int cpu),
int (*teardown)(unsigned int cpu))
{
return __cpuhp_setup_state(state, name, false, startup, teardown,
false);
}
static inline int cpuhp_setup_state_nocalls_cpuslocked(enum cpuhp_state state,
const char *name,
int (*startup)(unsigned int cpu),
int (*teardown)(unsigned int cpu))
{
return __cpuhp_setup_state_cpuslocked(state, name, false, startup,
teardown, false);
}
/**
* cpuhp_setup_state_multi - Add callbacks for multi state
* @state: The state for which the calls are installed
* @name: Name of the callback.
* @startup: startup callback function
* @teardown: teardown callback function
*
* Sets the internal multi_instance flag and prepares a state to work as a multi
* instance callback. No callbacks are invoked at this point. The callbacks are
* invoked once an instance for this state are registered via
* @cpuhp_state_add_instance or @cpuhp_state_add_instance_nocalls.
*/
static inline int cpuhp_setup_state_multi(enum cpuhp_state state,
const char *name,
int (*startup)(unsigned int cpu,
struct hlist_node *node),
int (*teardown)(unsigned int cpu,
struct hlist_node *node))
{
return __cpuhp_setup_state(state, name, false,
(void *) startup,
(void *) teardown, true);
}
int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
bool invoke);
int __cpuhp_state_add_instance_cpuslocked(enum cpuhp_state state,
struct hlist_node *node, bool invoke);
/**
* cpuhp_state_add_instance - Add an instance for a state and invoke startup
* callback.
* @state: The state for which the instance is installed
* @node: The node for this individual state.
*
* Installs the instance for the @state and invokes the startup callback on
* the present cpus which have already reached the @state. The @state must have
* been earlier marked as multi-instance by @cpuhp_setup_state_multi.
*/
static inline int cpuhp_state_add_instance(enum cpuhp_state state,
struct hlist_node *node)
{
return __cpuhp_state_add_instance(state, node, true);
}
/**
* cpuhp_state_add_instance_nocalls - Add an instance for a state without
* invoking the startup callback.
* @state: The state for which the instance is installed
* @node: The node for this individual state.
*
* Installs the instance for the @state The @state must have been earlier
* marked as multi-instance by @cpuhp_setup_state_multi.
*/
static inline int cpuhp_state_add_instance_nocalls(enum cpuhp_state state,
struct hlist_node *node)
{
return __cpuhp_state_add_instance(state, node, false);
}
static inline int
cpuhp_state_add_instance_nocalls_cpuslocked(enum cpuhp_state state,
struct hlist_node *node)
{
return __cpuhp_state_add_instance_cpuslocked(state, node, false);
}
void __cpuhp_remove_state(enum cpuhp_state state, bool invoke);
void __cpuhp_remove_state_cpuslocked(enum cpuhp_state state, bool invoke);
/**
* cpuhp_remove_state - Remove hotplug state callbacks and invoke the teardown
* @state: The state for which the calls are removed
*
* Removes the callback functions and invokes the teardown callback on
* the present cpus which have already reached the @state.
*/
static inline void cpuhp_remove_state(enum cpuhp_state state)
{
__cpuhp_remove_state(state, true);
}
/**
* cpuhp_remove_state_nocalls - Remove hotplug state callbacks without invoking
* teardown
* @state: The state for which the calls are removed
*/
static inline void cpuhp_remove_state_nocalls(enum cpuhp_state state)
{
__cpuhp_remove_state(state, false);
}
static inline void cpuhp_remove_state_nocalls_cpuslocked(enum cpuhp_state state)
{
__cpuhp_remove_state_cpuslocked(state, false);
}
/**
* cpuhp_remove_multi_state - Remove hotplug multi state callback
* @state: The state for which the calls are removed
*
* Removes the callback functions from a multi state. This is the reverse of
* cpuhp_setup_state_multi(). All instances should have been removed before
* invoking this function.
*/
static inline void cpuhp_remove_multi_state(enum cpuhp_state state)
{
__cpuhp_remove_state(state, false);
}
int __cpuhp_state_remove_instance(enum cpuhp_state state,
struct hlist_node *node, bool invoke);
/**
* cpuhp_state_remove_instance - Remove hotplug instance from state and invoke
* the teardown callback
* @state: The state from which the instance is removed
* @node: The node for this individual state.
*
* Removes the instance and invokes the teardown callback on the present cpus
* which have already reached the @state.
*/
static inline int cpuhp_state_remove_instance(enum cpuhp_state state,
struct hlist_node *node)
{
return __cpuhp_state_remove_instance(state, node, true);
}
/**
* cpuhp_state_remove_instance_nocalls - Remove hotplug instance from state
* without invoking the reatdown callback
* @state: The state from which the instance is removed
* @node: The node for this individual state.
*
* Removes the instance without invoking the teardown callback.
*/
static inline int cpuhp_state_remove_instance_nocalls(enum cpuhp_state state,
struct hlist_node *node)
{
return __cpuhp_state_remove_instance(state, node, false);
}
#ifdef CONFIG_SMP
void cpuhp_online_idle(enum cpuhp_state state);
#else
static inline void cpuhp_online_idle(enum cpuhp_state state) { }
#endif
#endif