Re: [PATCH] hmp: Add "calc_dirty_rate" and "info dirty_rate" cmds

[Hyman]

在 2021/6/1 8:57, Peter Xu 写道:
> These two commands are missing when adding the QMP sister commands.  Add them,
> so developers can play with them easier.
>
> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Cc: Juan Quintela <quintela@redhat.com>
> Cc: Leonardo Bras Soares Passos <lsoaresp@redhat.com>
> Cc: Chuan Zheng <zhengchuan@huawei.com>
> Cc: huangy81@chinatelecom.cn
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
> PS: I really doubt whether this is working as expected... I ran one 200MB/s
> workload inside, what I measured is 20MB/s with current algorithm...  Sampling
> 512 pages out of 1G mem is not wise enough I guess, especially that assumes
> dirty workload is spread across the memories while it's normally not the case..
I doubt whether the sampling can cope with the situation that the guest 
dirty memory too fast so that the sampling within a given time can not 
finish, this may happens when vm is in large scale.
> ---
>   hmp-commands-info.hx  | 13 +++++++++++++
>   hmp-commands.hx       | 14 ++++++++++++++
>   include/monitor/hmp.h |  2 ++
>   migration/dirtyrate.c | 43 +++++++++++++++++++++++++++++++++++++++++++
>   4 files changed, 72 insertions(+)
>
> diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
> index ab0c7aa5eea..f8a9141dd8a 100644
> --- a/hmp-commands-info.hx
> +++ b/hmp-commands-info.hx
> @@ -880,3 +880,16 @@ SRST
>     ``info replay``
>       Display the record/replay information: mode and the current icount.
>   ERST
> +
> +    {
> +        .name       = "dirty_rate",
> +        .args_type  = "",
> +        .params     = "",
> +        .help       = "show dirty rate information",
> +        .cmd        = hmp_info_dirty_rate,
> +    },
> +
> +SRST
> +  ``info dirty_rate``
> +    Display the vcpu dirty rate information.
> +ERST
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index 2d21fe5ad42..4c27fb91f7d 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -1727,3 +1727,17 @@ ERST
>           .flags      = "p",
>       },
>   
> +SRST
> +``calc_dirty_rate`` *second*
> +  Start a round of dirty rate measurement with the period specified in 
> *second*.
> +  The result of the dirty rate measurement may be observed with ``info
> +  dirty_rate`` command.
> +ERST
> +
> +    {
> +        .name       = "calc_dirty_rate",
> +        .args_type  = "second:l",
> +        .params     = "second",
> +        .help       = "start a round of guest dirty rate measurement",
> +        .cmd        = hmp_calc_dirty_rate,
> +    },
> diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
> index 605d57287ae..3baa1058e2c 100644
> --- a/include/monitor/hmp.h
> +++ b/include/monitor/hmp.h
> @@ -129,5 +129,7 @@ void hmp_info_replay(Monitor *mon, const QDict *qdict);
>   void hmp_replay_break(Monitor *mon, const QDict *qdict);
>   void hmp_replay_delete_break(Monitor *mon, const QDict *qdict);
>   void hmp_replay_seek(Monitor *mon, const QDict *qdict);
> +void hmp_info_dirty_rate(Monitor *mon, const QDict *qdict);
> +void hmp_calc_dirty_rate(Monitor *mon, const QDict *qdict);
>   
>   #endif
> diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
> index ccb98147e89..382287d2912 100644
> --- a/migration/dirtyrate.c
> +++ b/migration/dirtyrate.c
> @@ -20,6 +20,9 @@
>   #include "ram.h"
>   #include "trace.h"
>   #include "dirtyrate.h"
> +#include "monitor/hmp.h"
> +#include "monitor/monitor.h"
> +#include "qapi/qmp/qdict.h"
>   
>   static int CalculatingState = DIRTY_RATE_STATUS_UNSTARTED;
>   static struct DirtyRateStat DirtyStat;
> @@ -424,3 +427,43 @@ struct DirtyRateInfo *qmp_query_dirty_rate(Error **errp)
>   {
>       return query_dirty_rate_info();
>   }
> +
> +void hmp_info_dirty_rate(Monitor *mon, const QDict *qdict)
> +{
> +    DirtyRateInfo *info = query_dirty_rate_info();
> +
> +    monitor_printf(mon, "Status: %s\n",
> +                   DirtyRateStatus_str(info->status));
> +    monitor_printf(mon, "Start Time: %"PRIi64" (ms)\n",
> +                   info->start_time);
> +    monitor_printf(mon, "Period: %"PRIi64" (sec)\n",
> +                   info->calc_time);
> +    monitor_printf(mon, "Dirty rate: ");
> +    if (info->has_dirty_rate) {
> +        monitor_printf(mon, "%"PRIi64" (MB/s)\n", info->dirty_rate);
> +    } else {
> +        monitor_printf(mon, "(not ready)\n");
> +    }
> +    g_free(info);
> +}
> +
> +void hmp_calc_dirty_rate(Monitor *mon, const QDict *qdict)
> +{
> +    int64_t sec = qdict_get_try_int(qdict, "second", 0);
> +    Error *err = NULL;
> +
> +    if (!sec) {
> +        monitor_printf(mon, "Incorrect period length specified!\n");
> +        return;
> +    }
> +
> +    qmp_calc_dirty_rate(sec, &err);
> +    if (err) {
> +        hmp_handle_error(mon, err);
> +        return;
> +    }
> +
> +    monitor_printf(mon, "Starting dirty rate measurement with period %"PRIi64
> +                   " seconds\n", sec);
> +    monitor_printf(mon, "[Please use 'info dirty_rate' to check results]\n");
> +}