Re: [PATCH v5 07/12] migration/dirtyrate: Compare page hash results for recorded sampled page

[David Edmondson <dme@dme.org>]

On Monday, 2020-08-24 at 17:14:35 +08, Chuan Zheng wrote:

> Compare page hash results for recorded sampled page.
>
> Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
> Signed-off-by: YanYing Zhuang <ann.zhuangyanying@huawei.com>
> ---
>  migration/dirtyrate.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 64 insertions(+)
>
> diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
> index 66de426..050270d 100644
> --- a/migration/dirtyrate.c
> +++ b/migration/dirtyrate.c
> @@ -202,6 +202,70 @@ static int record_ramblock_hash_info(struct RamblockDirtyInfo **block_dinfo,
>      return 0;
>  }
>  
> +static int calc_page_dirty_rate(struct RamblockDirtyInfo *info)

This never fails - could be void?

> +{
> +    uint32_t crc;
> +    int i;
> +
> +    for (i = 0; i < info->sample_pages_count; i++) {
> +        crc = get_ramblock_vfn_hash(info, info->sample_page_vfn[i]);
> +        if (crc != info->hash_result[i]) {
> +            info->sample_dirty_count++;
> +        }
> +    }
> +
> +    return 0;
> +}
> +
> +static bool find_page_matched(RAMBlock *block, struct RamblockDirtyInfo *infos,
> +                              int count, struct RamblockDirtyInfo **matched)

This might as well just return a struct RamblockDirtyInfo pointer (or NULL).

> +{
> +    int i;
> +
> +    for (i = 0; i < count; i++) {
> +        if (!strcmp(infos[i].idstr, qemu_ram_get_idstr(block))) {
> +            break;
> +        }
> +    }
> +
> +    if (i == count) {
> +        return false;
> +    }
> +
> +    if (infos[i].ramblock_addr != qemu_ram_get_host_addr(block) ||
> +        infos[i].ramblock_pages !=
> +            (qemu_ram_get_used_length(block) >> DIRTYRATE_PAGE_SHIFT_KB)) {
> +        return false;
> +    }
> +
> +    *matched = &infos[i];
> +    return true;
> +}
> +
> +static int compare_page_hash_info(struct RamblockDirtyInfo *info,
> +                                  int block_index)
> +{
> +    struct RamblockDirtyInfo *block_dinfo = NULL;
> +    RAMBlock *block = NULL;
> +
> +    RAMBLOCK_FOREACH_MIGRATABLE(block) {
> +        block_dinfo = NULL;
> +        if (!find_page_matched(block, info, block_index + 1, &block_dinfo)) {
> +            continue;
> +        }
> +        if (calc_page_dirty_rate(block_dinfo) < 0) {
> +            return -1;
> +        }
> +        update_dirtyrate_stat(block_dinfo);
> +    }
> +
> +    if (!DirtyStat.total_sample_count) {
> +        return -1;
> +    }
> +
> +    return 0;
> +}
> +
>  static void calculate_dirtyrate(struct DirtyRateConfig config)
>  {
>      /* todo */
> -- 
> 1.8.3.1

dme.
-- 
Sometimes these eyes, forget the face they're peering from.