1 #ifndef _LINUX_PSI_TYPES_H 2 #define _LINUX_PSI_TYPES_H 3 4 #include <linux/kthread.h> 5 #include <linux/seqlock.h> 6 #include <linux/types.h> 7 #include <linux/kref.h> 8 #include <linux/wait.h> 9 10 #ifdef CONFIG_PSI 11 12 /* Tracked task states */ 13 enum psi_task_count { 14 NR_IOWAIT, 15 NR_MEMSTALL, 16 NR_RUNNING, 17 NR_PSI_TASK_COUNTS = 3, 18 }; 19 20 /* Task state bitmasks */ 21 #define TSK_IOWAIT (1 << NR_IOWAIT) 22 #define TSK_MEMSTALL (1 << NR_MEMSTALL) 23 #define TSK_RUNNING (1 << NR_RUNNING) 24 25 /* Resources that workloads could be stalled on */ 26 enum psi_res { 27 PSI_IO, 28 PSI_MEM, 29 PSI_CPU, 30 NR_PSI_RESOURCES = 3, 31 }; 32 33 /* 34 * Pressure states for each resource: 35 * 36 * SOME: Stalled tasks & working tasks 37 * FULL: Stalled tasks & no working tasks 38 */ 39 enum psi_states { 40 PSI_IO_SOME, 41 PSI_IO_FULL, 42 PSI_MEM_SOME, 43 PSI_MEM_FULL, 44 PSI_CPU_SOME, 45 /* Only per-CPU, to weigh the CPU in the global average: */ 46 PSI_NONIDLE, 47 NR_PSI_STATES = 6, 48 }; 49 50 enum psi_aggregators { 51 PSI_AVGS = 0, 52 PSI_POLL, 53 NR_PSI_AGGREGATORS, 54 }; 55 56 struct psi_group_cpu { 57 /* 1st cacheline updated by the scheduler */ 58 59 /* Aggregator needs to know of concurrent changes */ 60 seqcount_t seq ____cacheline_aligned_in_smp; 61 62 /* States of the tasks belonging to this group */ 63 unsigned int tasks[NR_PSI_TASK_COUNTS]; 64 65 /* Aggregate pressure state derived from the tasks */ 66 u32 state_mask; 67 68 /* Period time sampling buckets for each state of interest (ns) */ 69 u32 times[NR_PSI_STATES]; 70 71 /* Time of last task change in this group (rq_clock) */ 72 u64 state_start; 73 74 /* 2nd cacheline updated by the aggregator */ 75 76 /* Delta detection against the sampling buckets */ 77 u32 times_prev[NR_PSI_AGGREGATORS][NR_PSI_STATES] 78 ____cacheline_aligned_in_smp; 79 }; 80 81 /* PSI growth tracking window */ 82 struct psi_window { 83 /* Window size in ns */ 84 u64 size; 85 86 /* Start time of the current window in ns */ 87 u64 start_time; 88 89 /* Value at the start of the window */ 90 u64 start_value; 91 92 /* Value growth in the previous window */ 93 u64 prev_growth; 94 }; 95 96 struct psi_trigger { 97 /* PSI state being monitored by the trigger */ 98 enum psi_states state; 99 100 /* User-spacified threshold in ns */ 101 u64 threshold; 102 103 /* List node inside triggers list */ 104 struct list_head node; 105 106 /* Backpointer needed during trigger destruction */ 107 struct psi_group *group; 108 109 /* Wait queue for polling */ 110 wait_queue_head_t event_wait; 111 112 /* Pending event flag */ 113 int event; 114 115 /* Tracking window */ 116 struct psi_window win; 117 118 /* 119 * Time last event was generated. Used for rate-limiting 120 * events to one per window 121 */ 122 u64 last_event_time; 123 124 /* Refcounting to prevent premature destruction */ 125 struct kref refcount; 126 }; 127 128 struct psi_group { 129 /* Protects data used by the aggregator */ 130 struct mutex avgs_lock; 131 132 /* Per-cpu task state & time tracking */ 133 struct psi_group_cpu __percpu *pcpu; 134 135 /* Running pressure averages */ 136 u64 avg_total[NR_PSI_STATES - 1]; 137 u64 avg_last_update; 138 u64 avg_next_update; 139 140 /* Aggregator work control */ 141 struct delayed_work avgs_work; 142 143 /* Total stall times and sampled pressure averages */ 144 u64 total[NR_PSI_AGGREGATORS][NR_PSI_STATES - 1]; 145 unsigned long avg[NR_PSI_STATES - 1][3]; 146 147 /* Monitor work control */ 148 atomic_t poll_scheduled; 149 struct kthread_worker __rcu *poll_kworker; 150 struct kthread_delayed_work poll_work; 151 152 /* Protects data used by the monitor */ 153 struct mutex trigger_lock; 154 155 /* Configured polling triggers */ 156 struct list_head triggers; 157 u32 nr_triggers[NR_PSI_STATES - 1]; 158 u32 poll_states; 159 u64 poll_min_period; 160 161 /* Total stall times at the start of monitor activation */ 162 u64 polling_total[NR_PSI_STATES - 1]; 163 u64 polling_next_update; 164 u64 polling_until; 165 }; 166 167 #else /* CONFIG_PSI */ 168 169 struct psi_group { }; 170 171 #endif /* CONFIG_PSI */ 172 173 #endif /* _LINUX_PSI_TYPES_H */ 174
