Re: [Qemu-devel] [PATCH 08/14] migration: remove unfreeze logic

[Paolo Bonzini <pbonzini@redhat.com>]

Il 21/09/2012 16:08, Juan Quintela ha scritto:
> Now that we have a thread, and blocking writes, we don't need it.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  buffered_file.c | 24 +-----------------------
>  migration.c     | 23 -----------------------
>  migration.h     |  1 -
>  3 files changed, 1 insertion(+), 47 deletions(-)
> 
> diff --git a/buffered_file.c b/buffered_file.c
> index 6c3d057..2c9859b 100644
> --- a/buffered_file.c
> +++ b/buffered_file.c
> @@ -26,7 +26,6 @@ typedef struct QEMUFileBuffered
>  {
>      MigrationState *migration_state;
>      QEMUFile *file;
> -    int freeze_output;
>      size_t bytes_xfer;
>      size_t xfer_limit;
>      uint8_t *buffer;
> @@ -70,13 +69,6 @@ static int buffered_flush(QEMUFileBuffered *s)
> 
>          ret = migrate_fd_put_buffer(s->migration_state, s->buffer + offset,
>                                      s->buffer_size - offset);
> -        if (ret == -EAGAIN) {
> -            DPRINTF("backend not ready, freezing\n");
> -            ret = 0;
> -            s->freeze_output = 1;
> -            break;
> -        }
> -
>          if (ret <= 0) {
>              DPRINTF("error flushing data, %zd\n", ret);
>              break;
> @@ -110,9 +102,6 @@ static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, in
>          return error;
>      }
> 
> -    DPRINTF("unfreezing output\n");
> -    s->freeze_output = 0;
> -
>      if (size > 0) {
>          DPRINTF("buffering %d bytes\n", size - offset);
>          buffered_append(s, buf, size);
> @@ -126,7 +115,7 @@ static int buffered_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, in
> 
>      if (pos == 0 && size == 0) {
>          DPRINTF("file is ready\n");
> -        if (!s->freeze_output && s->bytes_xfer < s->xfer_limit) {
> +        if (s->bytes_xfer < s->xfer_limit) {
>              DPRINTF("notifying client\n");
>              migrate_fd_put_ready(s->migration_state);
>          }
> @@ -148,12 +137,6 @@ static int buffered_close(void *opaque)
>          if (ret < 0) {
>              break;
>          }
> -        if (s->freeze_output) {
> -            ret = migrate_fd_wait_for_unfreeze(s->migration_state);
> -            if (ret < 0) {
> -                break;
> -            }
> -        }
>      }
> 
>      ret2 = migrate_fd_close(s->migration_state);
> @@ -180,8 +163,6 @@ static int buffered_rate_limit(void *opaque)
>      if (ret) {
>          return ret;
>      }
> -    if (s->freeze_output)
> -        return 1;
> 
>      if (s->bytes_xfer > s->xfer_limit)
>          return 1;
> @@ -226,9 +207,6 @@ static void *buffered_file_thread(void *opaque)
>          if (s->migration_state->complete) {
>              break;
>          }
> -        if (s->freeze_output) {
> -            continue;
> -        }
>          if (current_time >= expire_time) {
>              s->bytes_xfer = 0;
>              expire_time = current_time + BUFFER_DELAY;
> diff --git a/migration.c b/migration.c
> index a8b2f4a..29ee710 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -367,29 +367,6 @@ static void migrate_fd_cancel(MigrationState *s)
>      migrate_fd_cleanup(s);
>  }
> 
> -int migrate_fd_wait_for_unfreeze(MigrationState *s)
> -{
> -    int ret;
> -
> -    DPRINTF("wait for unfreeze\n");
> -    if (s->state != MIG_STATE_ACTIVE)
> -        return -EINVAL;
> -
> -    do {
> -        fd_set wfds;
> -
> -        FD_ZERO(&wfds);
> -        FD_SET(s->fd, &wfds);
> -
> -        ret = select(s->fd + 1, NULL, &wfds, NULL, NULL);
> -    } while (ret == -1 && (s->get_error(s)) == EINTR);
> -
> -    if (ret == -1) {
> -        return -s->get_error(s);
> -    }
> -    return 0;
> -}
> -
>  int migrate_fd_close(MigrationState *s)
>  {
>      return s->close(s);
> diff --git a/migration.h b/migration.h
> index a63c5d5..505f792 100644
> --- a/migration.h
> +++ b/migration.h
> @@ -82,7 +82,6 @@ void migrate_fd_connect(MigrationState *s);
>  ssize_t migrate_fd_put_buffer(MigrationState *s, const void *data,
>                                size_t size);
>  void migrate_fd_put_ready(MigrationState *s);
> -int migrate_fd_wait_for_unfreeze(MigrationState *s);
>  int migrate_fd_close(MigrationState *s);
> 
>  void add_migration_state_change_notifier(Notifier *notify);
> 

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>