]>
Commit | Line | Data |
---|---|---|
1 | /** | |
2 | * @file timer_int.c | |
3 | * | |
4 | * @remark Copyright 2002 OProfile authors | |
5 | * @remark Read the file COPYING | |
6 | * | |
7 | * @author John Levon <levon@movementarian.org> | |
8 | */ | |
9 | ||
10 | #include <linux/kernel.h> | |
11 | #include <linux/notifier.h> | |
12 | #include <linux/smp.h> | |
13 | #include <linux/oprofile.h> | |
14 | #include <linux/profile.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/cpu.h> | |
17 | #include <linux/hrtimer.h> | |
18 | #include <asm/irq_regs.h> | |
19 | #include <asm/ptrace.h> | |
20 | ||
21 | #include "oprof.h" | |
22 | ||
23 | static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer); | |
24 | static int ctr_running; | |
25 | ||
26 | static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer) | |
27 | { | |
28 | oprofile_add_sample(get_irq_regs(), 0); | |
29 | hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC)); | |
30 | return HRTIMER_RESTART; | |
31 | } | |
32 | ||
33 | static void __oprofile_hrtimer_start(void *unused) | |
34 | { | |
35 | struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer); | |
36 | ||
37 | if (!ctr_running) | |
38 | return; | |
39 | ||
40 | hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
41 | hrtimer->function = oprofile_hrtimer_notify; | |
42 | ||
43 | hrtimer_start(hrtimer, ns_to_ktime(TICK_NSEC), | |
44 | HRTIMER_MODE_REL_PINNED); | |
45 | } | |
46 | ||
47 | static int oprofile_hrtimer_start(void) | |
48 | { | |
49 | get_online_cpus(); | |
50 | ctr_running = 1; | |
51 | on_each_cpu(__oprofile_hrtimer_start, NULL, 1); | |
52 | put_online_cpus(); | |
53 | return 0; | |
54 | } | |
55 | ||
56 | static void __oprofile_hrtimer_stop(int cpu) | |
57 | { | |
58 | struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu); | |
59 | ||
60 | if (!ctr_running) | |
61 | return; | |
62 | ||
63 | hrtimer_cancel(hrtimer); | |
64 | } | |
65 | ||
66 | static void oprofile_hrtimer_stop(void) | |
67 | { | |
68 | int cpu; | |
69 | ||
70 | get_online_cpus(); | |
71 | for_each_online_cpu(cpu) | |
72 | __oprofile_hrtimer_stop(cpu); | |
73 | ctr_running = 0; | |
74 | put_online_cpus(); | |
75 | } | |
76 | ||
77 | static int __cpuinit oprofile_cpu_notify(struct notifier_block *self, | |
78 | unsigned long action, void *hcpu) | |
79 | { | |
80 | long cpu = (long) hcpu; | |
81 | ||
82 | switch (action) { | |
83 | case CPU_ONLINE: | |
84 | case CPU_ONLINE_FROZEN: | |
85 | smp_call_function_single(cpu, __oprofile_hrtimer_start, | |
86 | NULL, 1); | |
87 | break; | |
88 | case CPU_DEAD: | |
89 | case CPU_DEAD_FROZEN: | |
90 | __oprofile_hrtimer_stop(cpu); | |
91 | break; | |
92 | } | |
93 | return NOTIFY_OK; | |
94 | } | |
95 | ||
96 | static struct notifier_block __refdata oprofile_cpu_notifier = { | |
97 | .notifier_call = oprofile_cpu_notify, | |
98 | }; | |
99 | ||
100 | int __init oprofile_timer_init(struct oprofile_operations *ops) | |
101 | { | |
102 | int rc; | |
103 | ||
104 | rc = register_hotcpu_notifier(&oprofile_cpu_notifier); | |
105 | if (rc) | |
106 | return rc; | |
107 | ops->create_files = NULL; | |
108 | ops->setup = NULL; | |
109 | ops->shutdown = NULL; | |
110 | ops->start = oprofile_hrtimer_start; | |
111 | ops->stop = oprofile_hrtimer_stop; | |
112 | ops->cpu_type = "timer"; | |
113 | return 0; | |
114 | } | |
115 | ||
116 | void __exit oprofile_timer_exit(void) | |
117 | { | |
118 | unregister_hotcpu_notifier(&oprofile_cpu_notifier); | |
119 | } |