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// 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 const struct min_heap_callbacks callbacks = {
.less = io_timer_cmp,
.swp = NULL,
};
void bch2_io_timer_add(struct io_clock *clock, struct io_timer *timer)
{
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)
{
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 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);
}
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);
}
unsigned long bch2_kthread_io_clock_wait_once(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);
set_current_state(TASK_INTERRUPTIBLE);
if (!(kthread && kthread_should_stop())) {
cpu_timeout = schedule_timeout(cpu_timeout);
try_to_freeze();
}
__set_current_state(TASK_RUNNING);
bch2_io_timer_del(clock, &wait.io_timer);
return cpu_timeout;
}
void bch2_kthread_io_clock_wait(struct io_clock *clock,
u64 io_until, unsigned long cpu_timeout)
{
bool kthread = (current->flags & PF_KTHREAD) != 0;
while (!(kthread && kthread_should_stop()) &&
cpu_timeout &&
atomic64_read(&clock->now) < io_until)
cpu_timeout = bch2_kthread_io_clock_wait_once(clock, io_until, cpu_timeout);
}
static struct io_timer *get_expired_timer(struct io_clock *clock, u64 now)
{
struct io_timer *ret = NULL;
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;
}
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