1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_PSI_TYPES_H 3 #define _LINUX_PSI_TYPES_H 4 5 #include <linux/kthread.h> 6 #include <linux/seqlock.h> 7 #include <linux/types.h> 8 #include <linux/kref.h> 9 #include <linux/wait.h> 10 11 #ifdef CONFIG_PSI 12 13 /* Tracked task states */ 14 enum psi_task_count { 15 NR_IOWAIT, 16 NR_MEMSTALL, 17 NR_RUNNING, 18 /* 19 * For IO and CPU stalls the presence of running/oncpu tasks 20 * in the domain means a partial rather than a full stall. 21 * For memory it's not so simple because of page reclaimers: 22 * they are running/oncpu while representing a stall. To tell 23 * whether a domain has productivity left or not, we need to 24 * distinguish between regular running (i.e. productive) 25 * threads and memstall ones. 26 */ 27 NR_MEMSTALL_RUNNING, 28 NR_PSI_TASK_COUNTS = 4, 29 }; 30 31 /* Task state bitmasks */ 32 #define TSK_IOWAIT (1 << NR_IOWAIT) 33 #define TSK_MEMSTALL (1 << NR_MEMSTALL) 34 #define TSK_RUNNING (1 << NR_RUNNING) 35 #define TSK_MEMSTALL_RUNNING (1 << NR_MEMSTALL_RUNNING) 36 37 /* Only one task can be scheduled, no corresponding task count */ 38 #define TSK_ONCPU (1 << NR_PSI_TASK_COUNTS) 39 40 /* Resources that workloads could be stalled on */ 41 enum psi_res { 42 PSI_IO, 43 PSI_MEM, 44 PSI_CPU, 45 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 46 PSI_IRQ, 47 #endif 48 NR_PSI_RESOURCES, 49 }; 50 51 /* 52 * Pressure states for each resource: 53 * 54 * SOME: Stalled tasks & working tasks 55 * FULL: Stalled tasks & no working tasks 56 */ 57 enum psi_states { 58 PSI_IO_SOME, 59 PSI_IO_FULL, 60 PSI_MEM_SOME, 61 PSI_MEM_FULL, 62 PSI_CPU_SOME, 63 PSI_CPU_FULL, 64 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 65 PSI_IRQ_FULL, 66 #endif 67 /* Only per-CPU, to weigh the CPU in the global average: */ 68 PSI_NONIDLE, 69 NR_PSI_STATES, 70 }; 71 72 /* Use one bit in the state mask to track TSK_ONCPU */ 73 #define PSI_ONCPU (1 << NR_PSI_STATES) 74 75 enum psi_aggregators { 76 PSI_AVGS = 0, 77 PSI_POLL, 78 NR_PSI_AGGREGATORS, 79 }; 80 81 struct psi_group_cpu { 82 /* 1st cacheline updated by the scheduler */ 83 84 /* Aggregator needs to know of concurrent changes */ 85 seqcount_t seq ____cacheline_aligned_in_smp; 86 87 /* States of the tasks belonging to this group */ 88 unsigned int tasks[NR_PSI_TASK_COUNTS]; 89 90 /* Aggregate pressure state derived from the tasks */ 91 u32 state_mask; 92 93 /* Period time sampling buckets for each state of interest (ns) */ 94 u32 times[NR_PSI_STATES]; 95 96 /* Time of last task change in this group (rq_clock) */ 97 u64 state_start; 98 99 /* 2nd cacheline updated by the aggregator */ 100 101 /* Delta detection against the sampling buckets */ 102 u32 times_prev[NR_PSI_AGGREGATORS][NR_PSI_STATES] 103 ____cacheline_aligned_in_smp; 104 }; 105 106 /* PSI growth tracking window */ 107 struct psi_window { 108 /* Window size in ns */ 109 u64 size; 110 111 /* Start time of the current window in ns */ 112 u64 start_time; 113 114 /* Value at the start of the window */ 115 u64 start_value; 116 117 /* Value growth in the previous window */ 118 u64 prev_growth; 119 }; 120 121 struct psi_trigger { 122 /* PSI state being monitored by the trigger */ 123 enum psi_states state; 124 125 /* User-spacified threshold in ns */ 126 u64 threshold; 127 128 /* List node inside triggers list */ 129 struct list_head node; 130 131 /* Backpointer needed during trigger destruction */ 132 struct psi_group *group; 133 134 /* Wait queue for polling */ 135 wait_queue_head_t event_wait; 136 137 /* Pending event flag */ 138 int event; 139 140 /* Tracking window */ 141 struct psi_window win; 142 143 /* 144 * Time last event was generated. Used for rate-limiting 145 * events to one per window 146 */ 147 u64 last_event_time; 148 149 /* Deferred event(s) from previous ratelimit window */ 150 bool pending_event; 151 }; 152 153 struct psi_group { 154 struct psi_group *parent; 155 bool enabled; 156 157 /* Protects data used by the aggregator */ 158 struct mutex avgs_lock; 159 160 /* Per-cpu task state & time tracking */ 161 struct psi_group_cpu __percpu *pcpu; 162 163 /* Running pressure averages */ 164 u64 avg_total[NR_PSI_STATES - 1]; 165 u64 avg_last_update; 166 u64 avg_next_update; 167 168 /* Aggregator work control */ 169 struct delayed_work avgs_work; 170 171 /* Total stall times and sampled pressure averages */ 172 u64 total[NR_PSI_AGGREGATORS][NR_PSI_STATES - 1]; 173 unsigned long avg[NR_PSI_STATES - 1][3]; 174 175 /* Monitor work control */ 176 struct task_struct __rcu *poll_task; 177 struct timer_list poll_timer; 178 wait_queue_head_t poll_wait; 179 atomic_t poll_wakeup; 180 181 /* Protects data used by the monitor */ 182 struct mutex trigger_lock; 183 184 /* Configured polling triggers */ 185 struct list_head triggers; 186 u32 nr_triggers[NR_PSI_STATES - 1]; 187 u32 poll_states; 188 u64 poll_min_period; 189 190 /* Total stall times at the start of monitor activation */ 191 u64 polling_total[NR_PSI_STATES - 1]; 192 u64 polling_next_update; 193 u64 polling_until; 194 }; 195 196 #else /* CONFIG_PSI */ 197 198 #define NR_PSI_RESOURCES 0 199 200 struct psi_group { }; 201 202 #endif /* CONFIG_PSI */ 203 204 #endif /* _LINUX_PSI_TYPES_H */ 205