Re: [PATCH v5 10/10] hmp: add filtering of statistics by name

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Paolo Bonzini (pbonzini@redhat.com) wrote:
> Allow the user to request only a specific subset of statistics.
> This can be useful when working on a feature or optimization that is
> known to affect that statistic.
> 
> Extracted from a patch by Mark Kanda.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

I think that's OK, if you repost please fix up the commit message with
examples of the command with and without names.


Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Dave

> ---
>  hmp-commands-info.hx |  8 ++++----
>  monitor/hmp-cmds.c   | 35 ++++++++++++++++++++++++++---------
>  2 files changed, 30 insertions(+), 13 deletions(-)
> 
> diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
> index a67040443b..3ffa24bd67 100644
> --- a/hmp-commands-info.hx
> +++ b/hmp-commands-info.hx
> @@ -897,10 +897,10 @@ ERST
>  
>      {
>          .name       = "stats",
> -        .args_type  = "target:s,provider:s?",
> -        .params     = "target [provider]",
> -        .help       = "show statistics for the given target (vm or vcpu); optionally filter by "
> -                      "provider",
> +        .args_type  = "target:s,names:s?,provider:s?",
> +        .params     = "target [names] [provider]",
> +        .help       = "show statistics for the given target (vm or vcpu); optionally filter by"
> +                      "name (comma-separated list, or * for all) and provider",
>          .cmd        = hmp_info_stats,
>      },
>  
> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> index a71887e54c..8775f69ff1 100644
> --- a/monitor/hmp-cmds.c
> +++ b/monitor/hmp-cmds.c
> @@ -2359,10 +2359,12 @@ static void print_stats_results(Monitor *mon, StatsTarget target,
>  }
>  
>  /* Create the StatsFilter that is needed for an "info stats" invocation.  */
> -static StatsFilter *stats_filter(StatsTarget target, int cpu_index,
> -                                 StatsProvider provider)
> +static StatsFilter *stats_filter(StatsTarget target, const char *names,
> +                                 int cpu_index, StatsProvider provider)
>  {
>      StatsFilter *filter = g_malloc0(sizeof(*filter));
> +    StatsProvider provider_idx;
> +    StatsRequestList *request_list = NULL;
>  
>      filter->target = target;
>      switch (target) {
> @@ -2383,15 +2385,29 @@ static StatsFilter *stats_filter(StatsTarget target, int cpu_index,
>          break;
>      }
>  
> -    if (provider == STATS_PROVIDER__MAX) {
> +    if (!names && provider == STATS_PROVIDER__MAX) {
>          return filter;
>      }
>  
> -    /* "info stats" can only query either one or all the providers.  */
> +    /*
> +     * "info stats" can only query either one or all the providers.  Querying
> +     * by name, but not by provider, requires the creation of one filter per
> +     * provider.
> +     */
> +    for (provider_idx = 0; provider_idx < STATS_PROVIDER__MAX; provider_idx++) {
> +        if (provider == STATS_PROVIDER__MAX || provider == provider_idx) {
> +            StatsRequest *request = g_new0(StatsRequest, 1);
> +            request->provider = provider_idx;
> +            if (names && !g_str_equal(names, "*")) {
> +                request->has_names = true;
> +                request->names = strList_from_comma_list(names);
> +            }
> +            QAPI_LIST_PREPEND(request_list, request);
> +        }
> +    }
> +
>      filter->has_providers = true;
> -    filter->providers = g_new0(StatsRequestList, 1);
> -    filter->providers->value = g_new0(StatsRequest, 1);
> -    filter->providers->value->provider = provider;
> +    filter->providers = request_list;
>      return filter;
>  }
>  
> @@ -2399,6 +2415,7 @@ void hmp_info_stats(Monitor *mon, const QDict *qdict)
>  {
>      const char *target_str = qdict_get_str(qdict, "target");
>      const char *provider_str = qdict_get_try_str(qdict, "provider");
> +    const char *names = qdict_get_try_str(qdict, "names");
>  
>      StatsProvider provider = STATS_PROVIDER__MAX;
>      StatsTarget target;
> @@ -2429,11 +2446,11 @@ void hmp_info_stats(Monitor *mon, const QDict *qdict)
>  
>      switch (target) {
>      case STATS_TARGET_VM:
> -        filter = stats_filter(target, -1, provider);
> +        filter = stats_filter(target, names, -1, provider);
>          break;
>      case STATS_TARGET_VCPU: {}
>          int cpu_index = monitor_get_cpu_index(mon);
> -        filter = stats_filter(target, cpu_index, provider);
> +        filter = stats_filter(target, names, cpu_index, provider);
>          break;
>      default:
>          abort();
> -- 
> 2.36.1
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK