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