Re: [PATCH v5 03/12] migration/dirtyrate: Add RamlockDirtyInfo to store sampled page info

[David Edmondson <dme@dme.org>]

On Monday, 2020-08-24 at 17:14:31 +08, Chuan Zheng wrote:

> Add RamlockDirtyInfo to store sampled page info of each ramblock.
>
> Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
> ---
>  migration/dirtyrate.h | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
>
> diff --git a/migration/dirtyrate.h b/migration/dirtyrate.h
> index 33669b7..70000da 100644
> --- a/migration/dirtyrate.h
> +++ b/migration/dirtyrate.h
> @@ -19,6 +19,11 @@
>   */
>  #define DIRTYRATE_DEFAULT_SAMPLE_PAGES            512
>  
> +/*
> + * Record ramblock idstr
> + */
> +#define RAMBLOCK_INFO_MAX_LEN                     256
> +
>  /* Take 1s as default for calculation duration */
>  #define DEFAULT_FETCH_DIRTYRATE_TIME_SEC          1
>  
> @@ -27,6 +32,19 @@ struct DirtyRateConfig {
>      int64_t sample_period_seconds; /* time duration between two sampling */
>  };
>  
> +/*
> + * Store dirtypage info for each ramblock.
> + */
> +struct RamblockDirtyInfo {
> +    char idstr[RAMBLOCK_INFO_MAX_LEN]; /* idstr for each ramblock */
> +    uint8_t *ramblock_addr; /* base address of ramblock we measure */
> +    uint64_t ramblock_pages; /* ramblock size in 4K-page */

It's probably a stupid question, but why not store a pointer to the
RAMBlock rather than copying some of the details?

> +    uint64_t *sample_page_vfn; /* relative offset address for sampled page */
> +    uint64_t sample_pages_count; /* count of sampled pages */
> +    uint64_t sample_dirty_count; /* cout of dirty pages we measure */

"cout" -> "count"

> +    uint32_t *hash_result; /* array of hash result for sampled pages */
> +};
> +
>  void *get_dirtyrate_thread(void *arg);
>  #endif
>  
> -- 
> 1.8.3.1

dme.
-- 
Please forgive me if I act a little strange, for I know not what I do.