#ifndef _LINUX_PSI_TYPES_H
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#define _LINUX_PSI_TYPES_H
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#include <linux/kthread.h>
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#include <linux/seqlock.h>
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#include <linux/types.h>
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#include <linux/kref.h>
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#include <linux/wait.h>
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#ifdef CONFIG_PSI
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/* Tracked task states */
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enum psi_task_count {
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NR_IOWAIT,
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NR_MEMSTALL,
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NR_RUNNING,
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/*
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* This can't have values other than 0 or 1 and could be
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* implemented as a bit flag. But for now we still have room
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* in the first cacheline of psi_group_cpu, and this way we
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* don't have to special case any state tracking for it.
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*/
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NR_ONCPU,
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NR_PSI_TASK_COUNTS = 4,
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};
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/* Task state bitmasks */
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#define TSK_IOWAIT (1 << NR_IOWAIT)
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#define TSK_MEMSTALL (1 << NR_MEMSTALL)
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#define TSK_RUNNING (1 << NR_RUNNING)
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#define TSK_ONCPU (1 << NR_ONCPU)
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/* Resources that workloads could be stalled on */
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enum psi_res {
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PSI_IO,
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PSI_MEM,
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PSI_CPU,
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NR_PSI_RESOURCES = 3,
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};
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/*
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* Pressure states for each resource:
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*
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* SOME: Stalled tasks & working tasks
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* FULL: Stalled tasks & no working tasks
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*/
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enum psi_states {
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PSI_IO_SOME,
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PSI_IO_FULL,
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PSI_MEM_SOME,
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PSI_MEM_FULL,
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PSI_CPU_SOME,
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/* Only per-CPU, to weigh the CPU in the global average: */
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PSI_NONIDLE,
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NR_PSI_STATES = 6,
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};
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enum psi_aggregators {
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PSI_AVGS = 0,
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PSI_POLL,
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NR_PSI_AGGREGATORS,
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};
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struct psi_group_cpu {
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/* 1st cacheline updated by the scheduler */
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/* Aggregator needs to know of concurrent changes */
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seqcount_t seq ____cacheline_aligned_in_smp;
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/* States of the tasks belonging to this group */
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unsigned int tasks[NR_PSI_TASK_COUNTS];
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/* Aggregate pressure state derived from the tasks */
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u32 state_mask;
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/* Period time sampling buckets for each state of interest (ns) */
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u32 times[NR_PSI_STATES];
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/* Time of last task change in this group (rq_clock) */
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u64 state_start;
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/* 2nd cacheline updated by the aggregator */
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/* Delta detection against the sampling buckets */
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u32 times_prev[NR_PSI_AGGREGATORS][NR_PSI_STATES]
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____cacheline_aligned_in_smp;
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};
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/* PSI growth tracking window */
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struct psi_window {
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/* Window size in ns */
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u64 size;
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/* Start time of the current window in ns */
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u64 start_time;
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/* Value at the start of the window */
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u64 start_value;
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/* Value growth in the previous window */
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u64 prev_growth;
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};
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struct psi_trigger {
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/* PSI state being monitored by the trigger */
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enum psi_states state;
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/* User-spacified threshold in ns */
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u64 threshold;
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/* List node inside triggers list */
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struct list_head node;
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/* Backpointer needed during trigger destruction */
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struct psi_group *group;
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/* Wait queue for polling */
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wait_queue_head_t event_wait;
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/* Pending event flag */
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int event;
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/* Tracking window */
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struct psi_window win;
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/*
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* Time last event was generated. Used for rate-limiting
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* events to one per window
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*/
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u64 last_event_time;
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};
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struct psi_group {
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/* Protects data used by the aggregator */
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struct mutex avgs_lock;
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/* Per-cpu task state & time tracking */
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struct psi_group_cpu __percpu *pcpu;
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/* Running pressure averages */
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u64 avg_total[NR_PSI_STATES - 1];
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u64 avg_last_update;
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u64 avg_next_update;
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/* Aggregator work control */
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struct delayed_work avgs_work;
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/* Total stall times and sampled pressure averages */
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u64 total[NR_PSI_AGGREGATORS][NR_PSI_STATES - 1];
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unsigned long avg[NR_PSI_STATES - 1][3];
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/* Monitor work control */
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struct task_struct __rcu *poll_task;
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struct timer_list poll_timer;
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wait_queue_head_t poll_wait;
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atomic_t poll_wakeup;
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atomic_t poll_scheduled;
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/* Protects data used by the monitor */
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struct mutex trigger_lock;
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/* Configured polling triggers */
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struct list_head triggers;
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u32 nr_triggers[NR_PSI_STATES - 1];
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u32 poll_states;
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u64 poll_min_period;
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/* Total stall times at the start of monitor activation */
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u64 polling_total[NR_PSI_STATES - 1];
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u64 polling_next_update;
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u64 polling_until;
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};
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#else /* CONFIG_PSI */
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struct psi_group { };
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#endif /* CONFIG_PSI */
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#endif /* _LINUX_PSI_TYPES_H */
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