include/linux/psi_types.h

   1 #ifndef _LINUX_PSI_TYPES_H
   2 #define _LINUX_PSI_TYPES_H
   3
   4 #include <linux/seqlock.h>
   5 #include <linux/types.h>
   6
   7 #ifdef CONFIG_PSI
   8
   9 /* Tracked task states */
  10 enum psi_task_count {
  11         NR_IOWAIT,
  12         NR_MEMSTALL,
  13         NR_RUNNING,
  14         NR_PSI_TASK_COUNTS = 3,
  15 };
  16
  17 /* Task state bitmasks */
  18 #define TSK_IOWAIT      (1 << NR_IOWAIT)
  19 #define TSK_MEMSTALL    (1 << NR_MEMSTALL)
  20 #define TSK_RUNNING     (1 << NR_RUNNING)
  21
  22 /* Resources that workloads could be stalled on */
  23 enum psi_res {
  24         PSI_IO,
  25         PSI_MEM,
  26         PSI_CPU,
  27         NR_PSI_RESOURCES = 3,
  28 };
  29
  30 /*
  31  * Pressure states for each resource:
  32  *
  33  * SOME: Stalled tasks & working tasks
  34  * FULL: Stalled tasks & no working tasks
  35  */
  36 enum psi_states {
  37         PSI_IO_SOME,
  38         PSI_IO_FULL,
  39         PSI_MEM_SOME,
  40         PSI_MEM_FULL,
  41         PSI_CPU_SOME,
  42         /* Only per-CPU, to weigh the CPU in the global average: */
  43         PSI_NONIDLE,
  44         NR_PSI_STATES = 6,
  45 };
  46
  47 struct psi_group_cpu {
  48         /* 1st cacheline updated by the scheduler */
  49
  50         /* Aggregator needs to know of concurrent changes */
  51         seqcount_t seq ____cacheline_aligned_in_smp;
  52
  53         /* States of the tasks belonging to this group */
  54         unsigned int tasks[NR_PSI_TASK_COUNTS];
  55
  56         /* Aggregate pressure state derived from the tasks */
  57         u32 state_mask;
  58
  59         /* Period time sampling buckets for each state of interest (ns) */
  60         u32 times[NR_PSI_STATES];
  61
  62         /* Time of last task change in this group (rq_clock) */
  63         u64 state_start;
  64
  65         /* 2nd cacheline updated by the aggregator */
  66
  67         /* Delta detection against the sampling buckets */
  68         u32 times_prev[NR_PSI_STATES] ____cacheline_aligned_in_smp;
  69 };
  70
  71 struct psi_group {
  72         /* Protects data updated during an aggregation */
  73         struct mutex stat_lock;
  74
  75         /* Per-cpu task state & time tracking */
  76         struct psi_group_cpu __percpu *pcpu;
  77
  78         /* Periodic aggregation state */
  79         u64 total_prev[NR_PSI_STATES - 1];
  80         u64 last_update;
  81         u64 next_update;
  82         struct delayed_work clock_work;
  83
  84         /* Total stall times and sampled pressure averages */
  85         u64 total[NR_PSI_STATES - 1];
  86         unsigned long avg[NR_PSI_STATES - 1][3];
  87 };
  88
  89 #else /* CONFIG_PSI */
  90
  91 struct psi_group { };
  92
  93 #endif /* CONFIG_PSI */
  94
  95 #endif /* _LINUX_PSI_TYPES_H */