Colo_checkpoint_notify use semaphore to notify COLO thread to do checkpoint.
If x-checkpoint-delay is set to be a very small value,The semaphore will
be accumulated.Even we change x-checkpoint-delay to be a big one,the checkpoint
will continue work for a long time.So we use condtion variable instead.
Signed-off-by: Wang Guang<wang.guan...@zte.com.cn>
Signed-off-by: Wang Yong<wang.yong...@zte.com.cn>
---
migration/colo.c | 19 ++++++++++++++++---
migration/migration.h | 7 +++++--
2 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/migration/colo.c b/migration/colo.c
index a425543..617ef23 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -442,7 +442,13 @@ static void colo_process_checkpoint(MigrationState *s)
goto out;
}
- qemu_sem_wait(&s->colo_checkpoint_sem);
+ qemu_mutex_lock(&s->colo_checkpoint_mutex);
+ while (!s->colo_checkpoint_is_signaled) {
+ qemu_cond_wait(&s->colo_checkpoint_cond,
+ &s->colo_checkpoint_mutex);
+ }
+ s->colo_checkpoint_is_signaled = false;
+ qemu_mutex_unlock(&s->colo_checkpoint_mutex);
ret = colo_do_checkpoint_transaction(s, bioc, fb);
if (ret < 0) {
@@ -465,6 +471,8 @@ out:
/* Hope this not to be too long to wait here */
qemu_sem_wait(&s->colo_exit_sem);
qemu_sem_destroy(&s->colo_exit_sem);
+ qemu_cond_destroy(&s->colo_checkpoint_cond);
+ qemu_mutex_destroy(&s->colo_checkpoint_mutex);
/*
* Must be called after failover BH is completed,
* Or the failover BH may shutdown the wrong fd that
@@ -480,7 +488,10 @@ void colo_checkpoint_notify(void *opaque)
MigrationState *s = opaque;
int64_t next_notify_time;
- qemu_sem_post(&s->colo_checkpoint_sem);
+ qemu_mutex_lock(&s->colo_checkpoint_mutex);
+ s->colo_checkpoint_is_signaled = true;
+ qemu_cond_signal(&s->colo_checkpoint_cond);
+ qemu_mutex_unlock(&s->colo_checkpoint_mutex);
s->colo_checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
next_notify_time = s->colo_checkpoint_time +
s->parameters.x_checkpoint_delay;
@@ -490,10 +501,12 @@ void colo_checkpoint_notify(void *opaque)
void migrate_start_colo_process(MigrationState *s)
{
qemu_mutex_unlock_iothread();
- qemu_sem_init(&s->colo_checkpoint_sem, 0);
s->colo_delay_timer = timer_new_ms(QEMU_CLOCK_HOST,
colo_checkpoint_notify, s);
+ qemu_cond_init(&s->colo_checkpoint_cond);
+ qemu_mutex_init(&s->colo_checkpoint_mutex);
+ s->colo_checkpoint_is_signaled = false;
qemu_sem_init(&s->colo_exit_sem, 0);
migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
MIGRATION_STATUS_COLO);
diff --git a/migration/migration.h b/migration/migration.h
index 148c9fa..9cdfedb 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -123,8 +123,11 @@ struct MigrationState
/* The semaphore is used to notify COLO thread that failover is finished */
QemuSemaphore colo_exit_sem;
- /* The semaphore is used to notify COLO thread to do checkpoint */
- QemuSemaphore colo_checkpoint_sem;
+ /* The Condtion Variable is used to notify COLO thread to do checkpoint */
+ QemuMutex colo_checkpoint_mutex;
+ QemuCond colo_checkpoint_cond;
+ bool colo_checkpoint_is_signaled;
+
int64_t colo_checkpoint_time;
QEMUTimer *colo_delay_timer;
--
1.8.3.1
