1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "clock.h"
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/preempt.h>
static inline bool io_timer_cmp(const void *l, const void *r, void __always_unused *args)
{
struct io_timer **_l = (struct io_timer **)l;
struct io_timer **_r = (struct io_timer **)r;
return (*_l)->expire < (*_r)->expire;
}
static inline void io_timer_swp(void *l, void *r, void __always_unused *args)
{
struct io_timer **_l = (struct io_timer **)l;
struct io_timer **_r = (struct io_timer **)r;
swap(*_l, *_r);
}
void bch2_io_timer_add(struct io_clock *clock, struct io_timer *timer)
{
const struct min_heap_callbacks callbacks = {
.less = io_timer_cmp,
.swp = io_timer_swp,
};
spin_lock(&clock->timer_lock);
if (time_after_eq64((u64) atomic64_read(&clock->now), timer->expire)) {
spin_unlock(&clock->timer_lock);
timer->fn(timer);
return;
}
for (size_t i = 0; i < clock->timers.nr; i++)
if (clock->timers.data[i] == timer)
goto out;
BUG_ON(!min_heap_push(&clock->timers, &timer, &callbacks, NULL));
out:
spin_unlock(&clock->timer_lock);
}
void bch2_io_timer_del(struct io_clock *clock, struct io_timer *timer)
{
const struct min_heap_callbacks callbacks = {
.less = io_timer_cmp,
.swp = io_timer_swp,
};
spin_lock(&clock->timer_lock);
for (size_t i = 0; i < clock->timers.nr; i++)
if (clock->timers.data[i] == timer) {
min_heap_del(&clock->timers, i, &callbacks, NULL);
break;
}
spin_unlock(&clock->timer_lock);
}
struct io_clock_wait {
struct io_timer io_timer;
struct timer_list cpu_timer;
struct task_struct *task;
int expired;
};
static void io_clock_wait_fn(struct io_timer *timer)
{
struct io_clock_wait *wait = container_of(timer,
struct io_clock_wait, io_timer);
wait->expired = 1;
wake_up_process(wait->task);
}
static void io_clock_cpu_timeout(struct timer_list *timer)
{
struct io_clock_wait *wait = container_of(timer,
struct io_clock_wait, cpu_timer);
wait->expired = 1;
wake_up_process(wait->task);
}
void bch2_io_clock_schedule_timeout(struct io_clock *clock, u64 until)
{
struct io_clock_wait wait = {
.io_timer.expire = until,
.io_timer.fn = io_clock_wait_fn,
.io_timer.fn2 = (void *) _RET_IP_,
.task = current,
};
bch2_io_timer_add(clock, &wait.io_timer);
schedule();
bch2_io_timer_del(clock, &wait.io_timer);
}
void bch2_kthread_io_clock_wait(struct io_clock *clock,
u64 io_until, unsigned long cpu_timeout)
{
bool kthread = (current->flags & PF_KTHREAD) != 0;
struct io_clock_wait wait = {
.io_timer.expire = io_until,
.io_timer.fn = io_clock_wait_fn,
.io_timer.fn2 = (void *) _RET_IP_,
.task = current,
};
bch2_io_timer_add(clock, &wait.io_timer);
timer_setup_on_stack(&wait.cpu_timer, io_clock_cpu_timeout, 0);
if (cpu_timeout != MAX_SCHEDULE_TIMEOUT)
mod_timer(&wait.cpu_timer, cpu_timeout + jiffies);
do {
set_current_state(TASK_INTERRUPTIBLE);
if (kthread && kthread_should_stop())
break;
if (wait.expired)
break;
schedule();
try_to_freeze();
} while (0);
__set_current_state(TASK_RUNNING);
del_timer_sync(&wait.cpu_timer);
destroy_timer_on_stack(&wait.cpu_timer);
bch2_io_timer_del(clock, &wait.io_timer);
}
static struct io_timer *get_expired_timer(struct io_clock *clock, u64 now)
{
struct io_timer *ret = NULL;
const struct min_heap_callbacks callbacks = {
.less = io_timer_cmp,
.swp = io_timer_swp,
};
if (clock->timers.nr &&
time_after_eq64(now, clock->timers.data[0]->expire)) {
ret = *min_heap_peek(&clock->timers);
min_heap_pop(&clock->timers, &callbacks, NULL);
}
return ret;
}
void __bch2_increment_clock(struct io_clock *clock, u64 sectors)
{
struct io_timer *timer;
u64 now = atomic64_add_return(sectors, &clock->now);
spin_lock(&clock->timer_lock);
while ((timer = get_expired_timer(clock, now)))
timer->fn(timer);
spin_unlock(&clock->timer_lock);
}
void bch2_io_timers_to_text(struct printbuf *out, struct io_clock *clock)
{
out->atomic++;
spin_lock(&clock->timer_lock);
u64 now = atomic64_read(&clock->now);
printbuf_tabstop_push(out, 40);
prt_printf(out, "current time:\t%llu\n", now);
for (unsigned i = 0; i < clock->timers.nr; i++)
prt_printf(out, "%ps %ps:\t%llu\n",
clock->timers.data[i]->fn,
clock->timers.data[i]->fn2,
clock->timers.data[i]->expire);
spin_unlock(&clock->timer_lock);
--out->atomic;
}
void bch2_io_clock_exit(struct io_clock *clock)
{
free_heap(&clock->timers);
free_percpu(clock->pcpu_buf);
}
int bch2_io_clock_init(struct io_clock *clock)
{
atomic64_set(&clock->now, 0);
spin_lock_init(&clock->timer_lock);
clock->max_slop = IO_CLOCK_PCPU_SECTORS * num_possible_cpus();
clock->pcpu_buf = alloc_percpu(*clock->pcpu_buf);
if (!clock->pcpu_buf)
return -BCH_ERR_ENOMEM_io_clock_init;
if (!init_heap(&clock->timers, NR_IO_TIMERS, GFP_KERNEL))
return -BCH_ERR_ENOMEM_io_clock_init;
return 0;
}
|
