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Date:   Fri, 12 Mar 2021 20:15:14 +0100
From:   Jiri Olsa <jolsa@redhat.com>
To:     Jin Yao <yao.jin@linux.intel.com>
Cc:     acme@kernel.org, jolsa@kernel.org, peterz@infradead.org,
        mingo@redhat.com, alexander.shishkin@linux.intel.com,
        Linux-kernel@vger.kernel.org, ak@linux.intel.com,
        kan.liang@intel.com, yao.jin@intel.com
Subject: Re: [PATCH v2 07/27] perf evlist: Hybrid event uses its own cpus
Message-ID: <YEu9wl4FcF+AoRTy@krava>
References: <20210311070742.9318-1-yao.jin@linux.intel.com>
 <20210311070742.9318-8-yao.jin@linux.intel.com>
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In-Reply-To: <20210311070742.9318-8-yao.jin@linux.intel.com>
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On Thu, Mar 11, 2021 at 03:07:22PM +0800, Jin Yao wrote:
> On hybrid platform, atom events can be only enabled on atom CPUs. Core
> events can be only enabled on core CPUs. So for a hybrid event, it can
> be only enabled on it's own CPUs.
> 
> But the problem for current perf is, the cpus for evsel (via PMU sysfs)
> have been merged to evsel_list->core.all_cpus. It might be all CPUs.
> 
> So we need to figure out one way to let the hybrid event only use it's
> own CPUs.
> 
> The idea is to create a new evlist__invalidate_all_cpus to invalidate
> the evsel_list->core.all_cpus then evlist__for_each_cpu returns cpu -1
> for hybrid evsel. If cpu is -1, hybrid evsel will use it's own cpus.

that's wild.. I don't understand when you say we don't have
cpus for evsel, because they have been merged.. each evsel
has evsel->core.own_cpus coming from pmu->cpus, right?

why can't you just filter out cpus that are in there?

jirka

> 
> We will see following code piece in patch.
> 
> if (cpu == -1 && !evlist->thread_mode)
>         evsel__enable_cpus(pos);
> 
> It lets the event be enabled on event's own cpus.
> 
> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
> ---
>  tools/perf/builtin-stat.c          | 37 ++++++++++++++-
>  tools/perf/util/evlist.c           | 72 ++++++++++++++++++++++++++++--
>  tools/perf/util/evlist.h           |  4 ++
>  tools/perf/util/evsel.h            |  8 ++++
>  tools/perf/util/python-ext-sources |  2 +
>  5 files changed, 117 insertions(+), 6 deletions(-)
> 
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 2e2e4a8345ea..68ecf68699a9 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -393,6 +393,18 @@ static int read_counter_cpu(struct evsel *counter, struct timespec *rs, int cpu)
>  	return 0;
>  }
>  
> +static int read_counter_cpus(struct evsel *counter, struct timespec *rs)
> +{
> +	int cpu, nr_cpus, err = 0;
> +	struct perf_cpu_map *cpus = evsel__cpus(counter);
> +
> +	nr_cpus = cpus ? cpus->nr : 1;
> +	for (cpu = 0; cpu < nr_cpus; cpu++)
> +		err = read_counter_cpu(counter, rs, cpu);
> +
> +	return err;
> +}
> +
>  static int read_affinity_counters(struct timespec *rs)
>  {
>  	struct evsel *counter;
> @@ -414,8 +426,14 @@ static int read_affinity_counters(struct timespec *rs)
>  			if (evsel__cpu_iter_skip(counter, cpu))
>  				continue;
>  			if (!counter->err) {
> -				counter->err = read_counter_cpu(counter, rs,
> -								counter->cpu_iter - 1);
> +				if (cpu == -1 && !evsel_list->thread_mode) {
> +					counter->err = read_counter_cpus(counter, rs);
> +				} else if (evsel_list->thread_mode) {
> +					counter->err = read_counter_cpu(counter, rs, 0);
> +				} else {
> +					counter->err = read_counter_cpu(counter, rs,
> +									counter->cpu_iter - 1);
> +				}
>  			}
>  		}
>  	}
> @@ -781,6 +799,21 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
>  	if (group)
>  		evlist__set_leader(evsel_list);
>  
> +	/*
> +	 * On hybrid platform, the cpus for evsel (via PMU sysfs) have been
> +	 * merged to evsel_list->core.all_cpus. We use evlist__invalidate_all_cpus
> +	 * to invalidate the evsel_list->core.all_cpus then evlist__for_each_cpu
> +	 * returns cpu -1 for hybrid evsel. If cpu is -1, hybrid evsel will
> +	 * use it's own cpus.
> +	 */
> +	if (evlist__has_hybrid_events(evsel_list)) {
> +		evlist__invalidate_all_cpus(evsel_list);
> +		if (!target__has_cpu(&target) ||
> +		    target__has_per_thread(&target)) {
> +			evsel_list->thread_mode = true;
> +		}
> +	}
> +
>  	if (affinity__setup(&affinity) < 0)
>  		return -1;
>  
> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
> index 882cd1f721d9..3ee12fcd0c9f 100644
> --- a/tools/perf/util/evlist.c
> +++ b/tools/perf/util/evlist.c
> @@ -381,7 +381,8 @@ bool evsel__cpu_iter_skip_no_inc(struct evsel *ev, int cpu)
>  bool evsel__cpu_iter_skip(struct evsel *ev, int cpu)
>  {
>  	if (!evsel__cpu_iter_skip_no_inc(ev, cpu)) {
> -		ev->cpu_iter++;
> +		if (cpu != -1)
> +			ev->cpu_iter++;
>  		return false;
>  	}
>  	return true;
> @@ -410,6 +411,16 @@ static int evlist__is_enabled(struct evlist *evlist)
>  	return false;
>  }
>  
> +static void evsel__disable_cpus(struct evsel *evsel)
> +{
> +	int cpu, nr_cpus;
> +	struct perf_cpu_map *cpus = evsel__cpus(evsel);
> +
> +	nr_cpus = cpus ? cpus->nr : 1;
> +	for (cpu = 0; cpu < nr_cpus; cpu++)
> +		evsel__disable_cpu(evsel, cpu);
> +}
> +
>  static void __evlist__disable(struct evlist *evlist, char *evsel_name)
>  {
>  	struct evsel *pos;
> @@ -436,7 +447,12 @@ static void __evlist__disable(struct evlist *evlist, char *evsel_name)
>  					has_imm = true;
>  				if (pos->immediate != imm)
>  					continue;
> -				evsel__disable_cpu(pos, pos->cpu_iter - 1);
> +				if (cpu == -1 && !evlist->thread_mode)
> +					evsel__disable_cpus(pos);
> +				else if (evlist->thread_mode)
> +					evsel__disable_cpu(pos, 0);
> +				else
> +					evsel__disable_cpu(pos, pos->cpu_iter - 1);
>  			}
>  		}
>  		if (!has_imm)
> @@ -472,6 +488,15 @@ void evlist__disable_evsel(struct evlist *evlist, char *evsel_name)
>  	__evlist__disable(evlist, evsel_name);
>  }
>  
> +static void evsel__enable_cpus(struct evsel *evsel)
> +{
> +	int cpu, nr_cpus;
> +	struct perf_cpu_map *cpus = evsel__cpus(evsel);
> +
> +	nr_cpus = cpus ? cpus->nr : 1;
> +	for (cpu = 0; cpu < nr_cpus; cpu++)
> +		evsel__enable_cpu(evsel, cpu);
> +}
>  static void __evlist__enable(struct evlist *evlist, char *evsel_name)
>  {
>  	struct evsel *pos;
> @@ -491,7 +516,12 @@ static void __evlist__enable(struct evlist *evlist, char *evsel_name)
>  				continue;
>  			if (!evsel__is_group_leader(pos) || !pos->core.fd)
>  				continue;
> -			evsel__enable_cpu(pos, pos->cpu_iter - 1);
> +                        if (cpu == -1 && !evlist->thread_mode)
> +                                evsel__enable_cpus(pos);
> +                        else if (evlist->thread_mode)
> +                                evsel__enable_cpu(pos, 0);
> +                        else
> +                                evsel__enable_cpu(pos, pos->cpu_iter - 1);
>  		}
>  	}
>  	affinity__cleanup(&affinity);
> @@ -1274,6 +1304,16 @@ void evlist__set_selected(struct evlist *evlist, struct evsel *evsel)
>  	evlist->selected = evsel;
>  }
>  
> +static void evsel__close_cpus(struct evsel *evsel)
> +{
> +	int cpu, nr_cpus;
> +	struct perf_cpu_map *cpus = evsel__cpus(evsel);
> +
> +	nr_cpus = cpus ? cpus->nr : 1;
> +	for (cpu = 0; cpu < nr_cpus; cpu++)
> +		perf_evsel__close_cpu(&evsel->core, cpu);
> +}
> +
>  void evlist__close(struct evlist *evlist)
>  {
>  	struct evsel *evsel;
> @@ -1298,7 +1338,13 @@ void evlist__close(struct evlist *evlist)
>  		evlist__for_each_entry_reverse(evlist, evsel) {
>  			if (evsel__cpu_iter_skip(evsel, cpu))
>  			    continue;
> -			perf_evsel__close_cpu(&evsel->core, evsel->cpu_iter - 1);
> +
> +			if (cpu == -1 && !evlist->thread_mode)
> +				evsel__close_cpus(evsel);
> +			else if (evlist->thread_mode)
> +				perf_evsel__close_cpu(&evsel->core, 0);
> +			else
> +				perf_evsel__close_cpu(&evsel->core, evsel->cpu_iter - 1);
>  		}
>  	}
>  	affinity__cleanup(&affinity);
> @@ -2130,3 +2176,21 @@ struct evsel *evlist__find_evsel(struct evlist *evlist, int idx)
>  	}
>  	return NULL;
>  }
> +
> +bool evlist__has_hybrid_events(struct evlist *evlist)
> +{
> +	struct evsel *evsel;
> +
> +	evlist__for_each_entry(evlist, evsel) {
> +		if (evsel__is_hybrid_event(evsel))
> +			return true;
> +	}
> +
> +	return false;
> +}
> +
> +void evlist__invalidate_all_cpus(struct evlist *evlist)
> +{
> +	perf_cpu_map__put(evlist->core.all_cpus);
> +	evlist->core.all_cpus = perf_cpu_map__empty_new(1);
> +}
> diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
> index b695ffaae519..0da683511d98 100644
> --- a/tools/perf/util/evlist.h
> +++ b/tools/perf/util/evlist.h
> @@ -52,6 +52,7 @@ struct evlist {
>  	struct perf_evlist core;
>  	int		 nr_groups;
>  	bool		 enabled;
> +	bool		 thread_mode;
>  	int		 id_pos;
>  	int		 is_pos;
>  	u64		 combined_sample_type;
> @@ -365,4 +366,7 @@ int evlist__ctlfd_ack(struct evlist *evlist);
>  #define EVLIST_DISABLED_MSG "Events disabled\n"
>  
>  struct evsel *evlist__find_evsel(struct evlist *evlist, int idx);
> +void evlist__invalidate_all_cpus(struct evlist *evlist);
> +
> +bool evlist__has_hybrid_events(struct evlist *evlist);
>  #endif /* __PERF_EVLIST_H */
> diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
> index 6026487353dd..69aadc52c1bd 100644
> --- a/tools/perf/util/evsel.h
> +++ b/tools/perf/util/evsel.h
> @@ -7,9 +7,11 @@
>  #include <sys/types.h>
>  #include <linux/perf_event.h>
>  #include <linux/types.h>
> +#include <string.h>
>  #include <internal/evsel.h>
>  #include <perf/evsel.h>
>  #include "symbol_conf.h"
> +#include "pmu-hybrid.h"
>  #include <internal/cpumap.h>
>  
>  struct bpf_object;
> @@ -435,4 +437,10 @@ struct perf_env *evsel__env(struct evsel *evsel);
>  int evsel__store_ids(struct evsel *evsel, struct evlist *evlist);
>  
>  void evsel__zero_per_pkg(struct evsel *evsel);
> +
> +static inline bool evsel__is_hybrid_event(struct evsel *evsel)
> +{
> +	return evsel->pmu_name && perf_pmu__is_hybrid(evsel->pmu_name);
> +}
> +
>  #endif /* __PERF_EVSEL_H */
> diff --git a/tools/perf/util/python-ext-sources b/tools/perf/util/python-ext-sources
> index 845dd46e3c61..d7c976671e3a 100644
> --- a/tools/perf/util/python-ext-sources
> +++ b/tools/perf/util/python-ext-sources
> @@ -37,3 +37,5 @@ util/units.c
>  util/affinity.c
>  util/rwsem.c
>  util/hashmap.c
> +util/pmu-hybrid.c
> +util/fncache.c
> -- 
> 2.17.1
>