On 02/15/2013 07:46 PM, Paolo Bonzini wrote:
> Accessing s->state outside the big QEMU lock will simplify a bit the
> locking/unlocking of the iothread lock.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> migration.c | 21 ++++++++++++---------
> 1 files changed, 12 insertions(+), 9 deletions(-)
>
> diff --git a/migration.c b/migration.c
> index b0b5578..a7f619b 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -281,14 +281,14 @@ static void migrate_fd_cleanup(MigrationState *s)
> void migrate_fd_error(MigrationState *s)
> {
> DPRINTF("setting error state\n");
> - s->state = MIG_STATE_ERROR;
> + __sync_val_compare_and_swap(&s->state, MIG_STATE_ACTIVE,
> MIG_STATE_ERROR);
> migrate_fd_cleanup(s);
> }
>
> static void migrate_fd_completed(MigrationState *s)
> {
> DPRINTF("setting completed state\n");
> - s->state = MIG_STATE_COMPLETED;
> + __sync_val_compare_and_swap(&s->state, MIG_STATE_ACTIVE,
> MIG_STATE_COMPLETED);
> migrate_fd_cleanup(s);
> }
>
> @@ -313,12 +313,9 @@ static ssize_t migrate_fd_put_buffer(MigrationState *s,
> const void *data,
>
> static void migrate_fd_cancel(MigrationState *s)
> {
> - if (s->state != MIG_STATE_ACTIVE)
> - return;
> -
> DPRINTF("cancelling migration\n");
>
> - s->state = MIG_STATE_CANCELLED;
> + __sync_val_compare_and_swap(&s->state, MIG_STATE_ACTIVE,
> MIG_STATE_CANCELLED);
> migrate_fd_cleanup(s);
> }
>
> @@ -651,12 +648,14 @@ static void *buffered_file_thread(void *opaque)
> qemu_mutex_lock_iothread();
> DPRINTF("beginning savevm\n");
> qemu_savevm_state_begin(s->file, &s->params);
> + qemu_mutex_unlock_iothread();
>
> while (s->state == MIG_STATE_ACTIVE) {
> int64_t current_time = qemu_get_clock_ms(rt_clock);
> uint64_t pending_size;
>
> if (s->bytes_xfer < s->xfer_limit) {
> + qemu_mutex_lock_iothread();
> DPRINTF("iterate\n");
> pending_size = qemu_savevm_state_pending(s->file, max_size);
> DPRINTF("pending size %lu max %lu\n", pending_size, max_size);
> @@ -672,8 +671,8 @@ static void *buffered_file_thread(void *opaque)
> qemu_savevm_state_complete(s->file);
> last_round = true;
> }
> + qemu_mutex_unlock_iothread();
> }
> - qemu_mutex_unlock_iothread();
> if (current_time >= initial_time + BUFFER_DELAY) {
> uint64_t transferred_bytes = s->bytes_xfer;
> uint64_t time_spent = current_time - initial_time;
> @@ -692,14 +691,18 @@ static void *buffered_file_thread(void *opaque)
> g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
> }
> buffered_flush(s);
> - qemu_mutex_lock_iothread();
> if (qemu_file_get_error(s->file)) {
> + qemu_mutex_lock_iothread();
> migrate_fd_error(s);
> + qemu_mutex_unlock_iothread();
> } else if (last_round && s->buffer_size == 0) {
> + qemu_mutex_lock_iothread();
> migrate_fd_completed(s);
> + qemu_mutex_unlock_iothread();
> }
> }
>
> + qemu_mutex_lock_iothread();
> if (s->state == MIG_STATE_COMPLETED) {
> int64_t end_time = qemu_get_clock_ms(rt_clock);
> s->total_time = end_time - s->total_time;
> @@ -711,8 +714,8 @@ static void *buffered_file_thread(void *opaque)
> vm_start();
> }
> }
> -
> qemu_mutex_unlock_iothread();
> +
> g_free(s->buffer);
> return NULL;
> }
>
Reviewed-by: Orit Wasserman <owass...@redhat.com>
