Re: [PATCH v2 2/4] migration/calc-dirty-rate: detailed stats in sampling mode

[Juan Quintela <quintela@redhat.com>]

<gudkov.andrei@huawei.com> wrote:
> On Mon, May 15, 2023 at 10:22:43AM +0200, Juan Quintela wrote:
>> <gudkov.andrei@huawei.com> wrote:
>> > On Wed, May 10, 2023 at 07:36:33PM +0200, Juan Quintela wrote:
>> >> Andrei Gudkov <gudkov.andrei@huawei.com> wrote:
>> >> > Collect number of dirty pages for progresseively increasing time
>> >> > periods starting with 125ms up to number of seconds specified with
>> >> > calc-dirty-rate. Report through qmp and hmp: 1) vector of dirty page
>> >> > measurements, 2) page size, 3) total number of VM pages, 4) number
>> >> > of sampled pages.
>> >> >
>> >> >  3 files changed, 160 insertions(+), 54 deletions(-)
>> >> >
>> >> > diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
>> >> > index acba3213a3..4491bbe91a 100644
>> >> > --- a/migration/dirtyrate.c
>> >> > +++ b/migration/dirtyrate.c
>> >> > @@ -224,6 +224,7 @@ static struct DirtyRateInfo *query_dirty_rate_info(void)
>> >> >      info->calc_time = DirtyStat.calc_time;
>> >> >      info->sample_pages = DirtyStat.sample_pages;
>> >> >      info->mode = dirtyrate_mode;
>> >> > +    info->page_size = TARGET_PAGE_SIZE;
>> >> 
>> >> I thought we exported this trough ""info migrate"
>> >> but we do it only if we are in the middle of a migration.  Perhaps we
>> >> should print it always.
>> >
>> > So, which one do you prefer? To keep it here or to make "info migrate" print it always (or both)?
>> 
>> info migrate to print it allways.  Thanks.
>
> I looked into "info migrate". To print page size irregarding migration status,
> all other 17 fields of MigrationInfo.ram will have to be made optional.
> Atop of that, it feels like that page size doesn't belong to "info migrate"
> since it is the only one "static" value, while all others are "dynamic" counters.
>
> I think I found a better place where page size can be reported --
> query-memory-size-summary. After the change it would be as following:
>   {"execute": "query-memory-size-summary"}
>   {"return": {"page-size": 4096, "base-memory": 34359738368, "plugged-memory": 0}}
>
> What do you think about it?

Perfect for me.

Thanks.