mirror of
https://github.com/torvalds/linux.git
synced 2024-11-14 08:02:07 +00:00
4b01a0b161
this call should use the array index j, not i. But with this approach, just one int i is enough, int j is not needed. Signed-off-by: Denis Cheng <crquan@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
93 lines
2.0 KiB
C
93 lines
2.0 KiB
C
|
|
#include <linux/wait.h>
|
|
#include <linux/backing-dev.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/module.h>
|
|
|
|
int bdi_init(struct backing_dev_info *bdi)
|
|
{
|
|
int i;
|
|
int err;
|
|
|
|
for (i = 0; i < NR_BDI_STAT_ITEMS; i++) {
|
|
err = percpu_counter_init_irq(&bdi->bdi_stat[i], 0);
|
|
if (err)
|
|
goto err;
|
|
}
|
|
|
|
bdi->dirty_exceeded = 0;
|
|
err = prop_local_init_percpu(&bdi->completions);
|
|
|
|
if (err) {
|
|
err:
|
|
while (i--)
|
|
percpu_counter_destroy(&bdi->bdi_stat[i]);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL(bdi_init);
|
|
|
|
void bdi_destroy(struct backing_dev_info *bdi)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < NR_BDI_STAT_ITEMS; i++)
|
|
percpu_counter_destroy(&bdi->bdi_stat[i]);
|
|
|
|
prop_local_destroy_percpu(&bdi->completions);
|
|
}
|
|
EXPORT_SYMBOL(bdi_destroy);
|
|
|
|
static wait_queue_head_t congestion_wqh[2] = {
|
|
__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]),
|
|
__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1])
|
|
};
|
|
|
|
|
|
void clear_bdi_congested(struct backing_dev_info *bdi, int rw)
|
|
{
|
|
enum bdi_state bit;
|
|
wait_queue_head_t *wqh = &congestion_wqh[rw];
|
|
|
|
bit = (rw == WRITE) ? BDI_write_congested : BDI_read_congested;
|
|
clear_bit(bit, &bdi->state);
|
|
smp_mb__after_clear_bit();
|
|
if (waitqueue_active(wqh))
|
|
wake_up(wqh);
|
|
}
|
|
EXPORT_SYMBOL(clear_bdi_congested);
|
|
|
|
void set_bdi_congested(struct backing_dev_info *bdi, int rw)
|
|
{
|
|
enum bdi_state bit;
|
|
|
|
bit = (rw == WRITE) ? BDI_write_congested : BDI_read_congested;
|
|
set_bit(bit, &bdi->state);
|
|
}
|
|
EXPORT_SYMBOL(set_bdi_congested);
|
|
|
|
/**
|
|
* congestion_wait - wait for a backing_dev to become uncongested
|
|
* @rw: READ or WRITE
|
|
* @timeout: timeout in jiffies
|
|
*
|
|
* Waits for up to @timeout jiffies for a backing_dev (any backing_dev) to exit
|
|
* write congestion. If no backing_devs are congested then just wait for the
|
|
* next write to be completed.
|
|
*/
|
|
long congestion_wait(int rw, long timeout)
|
|
{
|
|
long ret;
|
|
DEFINE_WAIT(wait);
|
|
wait_queue_head_t *wqh = &congestion_wqh[rw];
|
|
|
|
prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
|
|
ret = io_schedule_timeout(timeout);
|
|
finish_wait(wqh, &wait);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(congestion_wait);
|
|
|