Re: [Qemu-devel] [PATCH 3/4] migration: don't account sleep time for calculating bandwidth

[Orit Wasserman]

On 02/01/2013 02:32 PM, Juan Quintela wrote:
> While we are sleeping we are not sending, so we should not use that
> time to estimate our bandwidth.
Juan,
Maybe I missing something here but the sleep time is cause by the fact
we limit the migration bandwidth. So the available bandwidth should take
it into consideration? we still cape the bandwidth in the last stage.
Regards,
Orit
> 
> Signed-off-by: Juan Quintela <address@hidden>
> ---
>  migration.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/migration.c b/migration.c
> index 67abd12..64e75ca 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -666,6 +666,7 @@ static void *buffered_file_thread(void *opaque)
>  {
>      MigrationState *s = opaque;
>      int64_t initial_time = qemu_get_clock_ms(rt_clock);
> +    int64_t sleep_time = 0;
>      int64_t max_size = 0;
>      bool last_round = false;
>      int ret;
> @@ -738,7 +739,7 @@ static void *buffered_file_thread(void *opaque)
>          current_time = qemu_get_clock_ms(rt_clock);
>          if (current_time >= initial_time + BUFFER_DELAY) {
>              uint64_t transferred_bytes = s->bytes_xfer;
> -            uint64_t time_spent = current_time - initial_time;
> +            uint64_t time_spent = current_time - initial_time - sleep_time;
>              double bandwidth = transferred_bytes / time_spent;
>              max_size = bandwidth * migrate_max_downtime() / 1000000;
> 
> @@ -747,11 +748,13 @@ static void *buffered_file_thread(void *opaque)
>                      transferred_bytes, time_spent, bandwidth, max_size);
> 
>              s->bytes_xfer = 0;
> +            sleep_time = 0;
>              initial_time = current_time;
>          }
>          if (!last_round && (s->bytes_xfer >= s->xfer_limit)) {
>              /* usleep expects microseconds */
>              g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
> +            sleep_time += qemu_get_clock_ms(rt_clock) - current_time;
>          }
>          ret = buffered_flush(s);
>          if (ret < 0) {
>