Re: [PATCH v5 09/12] migration/dirtyrate: Implement get_sample_page_period() and block_sample_page_period()

[David Edmondson]

On Monday, 2020-08-24 at 17:14:37 +08, Chuan Zheng wrote:

> Implement get_sample_page_period() and set_sample_page_period() to
> sleep specific time between sample actions.
>
> Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
> ---
>  migration/dirtyrate.c | 24 ++++++++++++++++++++++++
>  migration/dirtyrate.h |  2 ++
>  2 files changed, 26 insertions(+)
>
> diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
> index bd398b7..d1c0a78 100644
> --- a/migration/dirtyrate.c
> +++ b/migration/dirtyrate.c
> @@ -28,6 +28,30 @@
>  static int CalculatingState = DIRTY_RATE_STATUS_UNSTARTED;
>  static struct DirtyRateStat DirtyStat;
>  
> +static int64_t set_sample_page_period(int64_t msec, int64_t initial_time)
> +{
> +    int64_t current_time;
> +
> +    current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
> +    if ((current_time - initial_time) >= msec) {
> +        msec = current_time - initial_time;
> +    } else {
> +        g_usleep((msec + initial_time - current_time) * 1000);
> +    }
> +
> +    return msec;
> +}
> +
> +static int64_t get_sample_page_period(int64_t sec)
> +{
> +    if (sec <= MIN_FETCH_DIRTYRATE_TIME_SEC ||

Shouldn't the minimum value be allowed?

That is, this test should be "sec < MIN_FETCH_DIRTYRATE_TIME_SEC" and
MIN_FETCH_DIRTYRATE_TIME_SEC should be 1.

> +        sec > MAX_FETCH_DIRTYRATE_TIME_SEC) {
> +        sec = DEFAULT_FETCH_DIRTYRATE_TIME_SEC;
> +    }
> +
> +    return sec;
> +}
> +
>  static int dirtyrate_set_state(int *state, int old_state, int new_state)
>  {
>      assert(new_state < DIRTY_RATE_STATUS__MAX);
> diff --git a/migration/dirtyrate.h b/migration/dirtyrate.h
> index 41bc264..50a5636 100644
> --- a/migration/dirtyrate.h
> +++ b/migration/dirtyrate.h
> @@ -51,6 +51,8 @@
>  
>  /* Take 1s as default for calculation duration */
>  #define DEFAULT_FETCH_DIRTYRATE_TIME_SEC          1
> +#define MIN_FETCH_DIRTYRATE_TIME_SEC              0
> +#define MAX_FETCH_DIRTYRATE_TIME_SEC              60
>  
>  struct DirtyRateConfig {
>      uint64_t sample_pages_per_gigabytes; /* sample pages per GB */
> -- 
> 1.8.3.1

dme.
-- 
Facts don't do what I want them to.