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99cf63c566
The soft lockup detector lacks a mechanism to identify interrupt storms as root cause of a lockup. To enable this the detector needs a mechanism to snapshot the interrupt count statistics on a CPU when the detector observes a potential lockup scenario and compare that against the interrupt count when it warns about the lockup later on. The number of interrupts in that period give a hint whether the lockup might have been caused by an interrupt storm. Instead of having extra storage in the lockup detector and accessing the internals of the interrupt descriptor directly, add a snapshot member to the per CPU irq_desc::kstat_irq structure and provide interfaces to take a snapshot of all interrupts on the current CPU and to retrieve the delta of a specific interrupt later on. Originally-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Bitao Hu <yaoma@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240411074134.30922-3-yaoma@linux.alibaba.com
146 lines
3.7 KiB
C
146 lines
3.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_KERNEL_STAT_H
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#define _LINUX_KERNEL_STAT_H
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#include <linux/smp.h>
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#include <linux/threads.h>
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#include <linux/percpu.h>
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#include <linux/cpumask.h>
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#include <linux/interrupt.h>
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#include <linux/sched.h>
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#include <linux/vtime.h>
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#include <asm/irq.h>
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/*
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* 'kernel_stat.h' contains the definitions needed for doing
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* some kernel statistics (CPU usage, context switches ...),
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* used by rstatd/perfmeter
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*/
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enum cpu_usage_stat {
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CPUTIME_USER,
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CPUTIME_NICE,
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CPUTIME_SYSTEM,
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CPUTIME_SOFTIRQ,
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CPUTIME_IRQ,
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CPUTIME_IDLE,
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CPUTIME_IOWAIT,
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CPUTIME_STEAL,
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CPUTIME_GUEST,
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CPUTIME_GUEST_NICE,
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#ifdef CONFIG_SCHED_CORE
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CPUTIME_FORCEIDLE,
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#endif
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NR_STATS,
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};
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struct kernel_cpustat {
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u64 cpustat[NR_STATS];
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};
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struct kernel_stat {
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unsigned long irqs_sum;
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unsigned int softirqs[NR_SOFTIRQS];
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};
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DECLARE_PER_CPU(struct kernel_stat, kstat);
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DECLARE_PER_CPU(struct kernel_cpustat, kernel_cpustat);
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/* Must have preemption disabled for this to be meaningful. */
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#define kstat_this_cpu this_cpu_ptr(&kstat)
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#define kcpustat_this_cpu this_cpu_ptr(&kernel_cpustat)
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#define kstat_cpu(cpu) per_cpu(kstat, cpu)
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#define kcpustat_cpu(cpu) per_cpu(kernel_cpustat, cpu)
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extern unsigned long long nr_context_switches_cpu(int cpu);
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extern unsigned long long nr_context_switches(void);
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extern unsigned int kstat_irqs_cpu(unsigned int irq, int cpu);
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extern void kstat_incr_irq_this_cpu(unsigned int irq);
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static inline void kstat_incr_softirqs_this_cpu(unsigned int irq)
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{
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__this_cpu_inc(kstat.softirqs[irq]);
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}
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static inline unsigned int kstat_softirqs_cpu(unsigned int irq, int cpu)
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{
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return kstat_cpu(cpu).softirqs[irq];
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}
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static inline unsigned int kstat_cpu_softirqs_sum(int cpu)
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{
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int i;
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unsigned int sum = 0;
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for (i = 0; i < NR_SOFTIRQS; i++)
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sum += kstat_softirqs_cpu(i, cpu);
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return sum;
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}
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#ifdef CONFIG_GENERIC_IRQ_STAT_SNAPSHOT
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extern void kstat_snapshot_irqs(void);
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extern unsigned int kstat_get_irq_since_snapshot(unsigned int irq);
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#else
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static inline void kstat_snapshot_irqs(void) { }
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static inline unsigned int kstat_get_irq_since_snapshot(unsigned int irq) { return 0; }
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#endif
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/*
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* Number of interrupts per specific IRQ source, since bootup
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*/
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extern unsigned int kstat_irqs_usr(unsigned int irq);
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/*
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* Number of interrupts per cpu, since bootup
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*/
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static inline unsigned long kstat_cpu_irqs_sum(unsigned int cpu)
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{
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return kstat_cpu(cpu).irqs_sum;
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}
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#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
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extern u64 kcpustat_field(struct kernel_cpustat *kcpustat,
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enum cpu_usage_stat usage, int cpu);
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extern void kcpustat_cpu_fetch(struct kernel_cpustat *dst, int cpu);
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#else
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static inline u64 kcpustat_field(struct kernel_cpustat *kcpustat,
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enum cpu_usage_stat usage, int cpu)
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{
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return kcpustat->cpustat[usage];
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}
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static inline void kcpustat_cpu_fetch(struct kernel_cpustat *dst, int cpu)
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{
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*dst = kcpustat_cpu(cpu);
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}
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#endif
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extern void account_user_time(struct task_struct *, u64);
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extern void account_guest_time(struct task_struct *, u64);
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extern void account_system_time(struct task_struct *, int, u64);
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extern void account_system_index_time(struct task_struct *, u64,
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enum cpu_usage_stat);
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extern void account_steal_time(u64);
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extern void account_idle_time(u64);
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extern u64 get_idle_time(struct kernel_cpustat *kcs, int cpu);
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#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
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static inline void account_process_tick(struct task_struct *tsk, int user)
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{
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vtime_flush(tsk);
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}
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#else
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extern void account_process_tick(struct task_struct *, int user);
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#endif
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extern void account_idle_ticks(unsigned long ticks);
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#ifdef CONFIG_SCHED_CORE
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extern void __account_forceidle_time(struct task_struct *tsk, u64 delta);
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#endif
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#endif /* _LINUX_KERNEL_STAT_H */
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