Linux kernel mirror (for testing)
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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 */
10enum psi_task_count {
11 NR_IOWAIT,
12 NR_MEMSTALL,
13 NR_RUNNING,
14 NR_PSI_TASK_COUNTS,
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 */
23enum psi_res {
24 PSI_IO,
25 PSI_MEM,
26 PSI_CPU,
27 NR_PSI_RESOURCES,
28};
29
30/*
31 * Pressure states for each resource:
32 *
33 * SOME: Stalled tasks & working tasks
34 * FULL: Stalled tasks & no working tasks
35 */
36enum 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,
45};
46
47struct 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 /* Period time sampling buckets for each state of interest (ns) */
57 u32 times[NR_PSI_STATES];
58
59 /* Time of last task change in this group (rq_clock) */
60 u64 state_start;
61
62 /* 2nd cacheline updated by the aggregator */
63
64 /* Delta detection against the sampling buckets */
65 u32 times_prev[NR_PSI_STATES] ____cacheline_aligned_in_smp;
66};
67
68struct psi_group {
69 /* Protects data updated during an aggregation */
70 struct mutex stat_lock;
71
72 /* Per-cpu task state & time tracking */
73 struct psi_group_cpu __percpu *pcpu;
74
75 /* Periodic aggregation state */
76 u64 total_prev[NR_PSI_STATES - 1];
77 u64 last_update;
78 u64 next_update;
79 struct delayed_work clock_work;
80
81 /* Total stall times and sampled pressure averages */
82 u64 total[NR_PSI_STATES - 1];
83 unsigned long avg[NR_PSI_STATES - 1][3];
84};
85
86#else /* CONFIG_PSI */
87
88struct psi_group { };
89
90#endif /* CONFIG_PSI */
91
92#endif /* _LINUX_PSI_TYPES_H */