Revision ff990d5952712c2e163b355946c39278da8407a8 authored by Uri Lublin on 22 February 2007, 15:37:32 UTC, committed by Avi Kivity on 04 March 2007, 09:12:43 UTC
Enabling dirty page logging is done using KVM_SET_MEMORY_REGION ioctl. If the memory region already exists, we need to remove write accesses, so writes will be caught, and dirty pages will be logged. Signed-off-by: Uri Lublin <uril@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
1 parent 02b27c1
backing-dev.c
#include <linux/wait.h>
#include <linux/backing-dev.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/module.h>
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);
/**
* congestion_end - wake up sleepers on a congested backing_dev_info
* @rw: READ or WRITE
*/
void congestion_end(int rw)
{
wait_queue_head_t *wqh = &congestion_wqh[rw];
if (waitqueue_active(wqh))
wake_up(wqh);
}
EXPORT_SYMBOL(congestion_end);
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