Re: [PATCH] perf report/annotate: Add option to specify a CPU range

[David Ahern <dsahern@gmail.com>]

On 06/29/2011 09:16 PM, Anton Blanchard wrote:
> 
> Add an option to perf report/annotate/script to specify which CPUs
> to operate on. This enables us to take a single system wide profile
> and analyse each CPU (or group of CPUs) in isolation.
> 
> This was useful when profiling a multiprocess workload where the
> bottleneck was on one CPU but this was hidden in the overall profile.
> Per process and per thread breakdowns didn't help because multiple
> processes were running on each CPU and no single process consumed
> an entire CPU.
> 
> The patch converts the list of CPUs returned by cpu_map__new into a
> bitmap for fast lookup. I wanted to use -C to be consistent with perf
> top/record/stat, but unfortunately perf report already uses -C <comms>.
> 
> Signed-off-by: Anton Blanchard <anton@samba.org>
> ---
> 
> v2: Incorporate suggestions from David Ahern:
> 	- Added -c to perf script
> 	- Check that SAMPLE_CPU is set when -c is used
> 	- Update documentation
> 
> Index: linux-2.6-tip/tools/perf/builtin-report.c
> ===================================================================
> --- linux-2.6-tip.orig/tools/perf/builtin-report.c	2011-06-30 11:35:08.488417534 +1000
> +++ linux-2.6-tip/tools/perf/builtin-report.c	2011-06-30 12:56:28.894807631 +1000
> @@ -33,6 +33,9 @@
>  #include "util/sort.h"
>  #include "util/hist.h"
>  
> +#include <linux/bitmap.h>
> +#include "util/cpumap.h"
> +
>  static char		const *input_name = "perf.data";
>  
>  static bool		force, use_tui, use_stdio;
> @@ -48,6 +51,9 @@ static const char	*pretty_printing_style
>  static char		callchain_default_opt[] = "fractal,0.5";
>  static symbol_filter_t	annotate_init;
>  
> +static const char	*cpu_list;
> +static DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
> +
>  static int perf_session__add_hist_entry(struct perf_session *session,
>  					struct addr_location *al,
>  					struct perf_sample *sample,
> @@ -116,6 +122,9 @@ static int process_sample_event(union pe
>  	if (al.filtered || (hide_unresolved && al.sym == NULL))
>  		return 0;
>  
> +	if (cpu_list && !test_bit(sample->cpu, cpu_bitmap))
> +		return 0;
> +
>  	if (al.map != NULL)
>  		al.map->dso->hit = 1;
>  
> @@ -262,6 +271,41 @@ static int __cmd_report(void)
>  	if (session == NULL)
>  		return -ENOMEM;
>  
> +	if (cpu_list) {
> +		int i;
> +		struct cpu_map *map;
> +
> +		for (i = 0; i < PERF_TYPE_MAX; ++i) {
> +			struct perf_evsel *evsel;
> +
> +			evsel = perf_session__find_first_evtype(session, i);
> +			if (!evsel)
> +				continue;
> +
> +			if (!(evsel->attr.sample_type & PERF_SAMPLE_CPU)) {
> +				pr_err("File does not contain CPU events. "
> +				       "Remove -c option to proceed.\n");
> +				ret = -1;
> +				goto out_delete;
> +			}
> +		}
> +
> +		map = cpu_map__new(cpu_list);
> +
> +		for (i = 0; i < map->nr; i++) {
> +			int cpu = map->map[i];
> +
> +			if (cpu >= MAX_NR_CPUS) {
> +				pr_err("Requested CPU %d too large. "
> +				       "Consider raising MAX_NR_CPUS\n", cpu);
> +				ret = -1;
> +				goto out_delete;
> +			}
> +
> +			set_bit(cpu, cpu_bitmap);
> +		}
> +	}
> +

It would be better to make this a function that all 3 commands reference
-- something like perf_session__cpu_bitmap(session, cpu_list,
cpu_bitmap) in util/session.c

David

>  	if (show_threads)
>  		perf_read_values_init(&show_threads_values);
>  
> @@ -455,6 +499,7 @@ static const struct option options[] = {
>  		    "Only display entries resolved to a symbol"),
>  	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
>  		    "Look for files with symbols relative to this directory"),
> +	OPT_STRING('c', "cpu", &cpu_list, "cpu", "list of cpus to profile"),
>  	OPT_END()
>  };
>  
> Index: linux-2.6-tip/tools/perf/builtin-annotate.c
> ===================================================================
> --- linux-2.6-tip.orig/tools/perf/builtin-annotate.c	2011-06-30 11:35:08.468417177 +1000
> +++ linux-2.6-tip/tools/perf/builtin-annotate.c	2011-06-30 12:56:35.514926037 +1000
> @@ -28,6 +28,9 @@
>  #include "util/hist.h"
>  #include "util/session.h"
>  
> +#include <linux/bitmap.h>
> +#include "util/cpumap.h"
> +
>  static char		const *input_name = "perf.data";
>  
>  static bool		force, use_tui, use_stdio;
> @@ -38,6 +41,9 @@ static bool		print_line;
>  
>  static const char *sym_hist_filter;
>  
> +static const char	*cpu_list;
> +static DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
> +
>  static int perf_evlist__add_sample(struct perf_evlist *evlist,
>  				   struct perf_sample *sample,
>  				   struct perf_evsel *evsel,
> @@ -90,6 +96,9 @@ static int process_sample_event(union pe
>  		return -1;
>  	}
>  
> +	if (cpu_list && !test_bit(sample->cpu, cpu_bitmap))
> +		return 0;
> +
>  	if (!al.filtered &&
>  	    perf_evlist__add_sample(session->evlist, sample, evsel, &al)) {
>  		pr_warning("problem incrementing symbol count, "
> @@ -177,6 +186,41 @@ static int __cmd_annotate(void)
>  	if (session == NULL)
>  		return -ENOMEM;
>  
> +	if (cpu_list) {
> +		int i;
> +		struct cpu_map *map;
> +
> +		for (i = 0; i < PERF_TYPE_MAX; ++i) {
> +			struct perf_evsel *evsel;
> +
> +			evsel = perf_session__find_first_evtype(session, i);
> +			if (!evsel)
> +				continue;
> +
> +			if (!(evsel->attr.sample_type & PERF_SAMPLE_CPU)) {
> +				pr_err("File does not contain CPU events. "
> +				       "Remove -c option to proceed.\n");
> +				ret = -1;
> +				goto out_delete;
> +			}
> +		}
> +
> +		map = cpu_map__new(cpu_list);
> +
> +		for (i = 0; i < map->nr; i++) {
> +			int cpu = map->map[i];
> +
> +			if (cpu >= MAX_NR_CPUS) {
> +				pr_err("Requested CPU %d too large. "
> +				       "Consider raising MAX_NR_CPUS\n", cpu);
> +				ret = -1;
> +				goto out_delete;
> +			}
> +
> +			set_bit(cpu, cpu_bitmap);
> +		}
> +	}
> +
>  	ret = perf_session__process_events(session, &event_ops);
>  	if (ret)
>  		goto out_delete;
> @@ -252,6 +296,7 @@ static const struct option options[] = {
>  		    "print matching source lines (may be slow)"),
>  	OPT_BOOLEAN('P', "full-paths", &full_paths,
>  		    "Don't shorten the displayed pathnames"),
> +	OPT_STRING('c', "cpu", &cpu_list, "cpu", "list of cpus to profile"),
>  	OPT_END()
>  };
>  
> Index: linux-2.6-tip/tools/perf/builtin-script.c
> ===================================================================
> --- linux-2.6-tip.orig/tools/perf/builtin-script.c	2011-06-30 11:35:08.478417356 +1000
> +++ linux-2.6-tip/tools/perf/builtin-script.c	2011-06-30 12:56:44.185081104 +1000
> @@ -13,6 +13,8 @@
>  #include "util/util.h"
>  #include "util/evlist.h"
>  #include "util/evsel.h"
> +#include <linux/bitmap.h>
> +#include "util/cpumap.h"
>  
>  static char const		*script_name;
>  static char const		*generate_script_lang;
> @@ -21,6 +23,8 @@ static u64			last_timestamp;
>  static u64			nr_unordered;
>  extern const struct option	record_options[];
>  static bool			no_callchain;
> +static const char		*cpu_list;
> +static DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
>  
>  enum perf_output_field {
>  	PERF_OUTPUT_COMM            = 1U << 0,
> @@ -453,6 +457,10 @@ static int process_sample_event(union pe
>  		last_timestamp = sample->time;
>  		return 0;
>  	}
> +
> +	if (cpu_list && !test_bit(sample->cpu, cpu_bitmap))
> +		return 0;
> +
>  	scripting_ops->process_event(event, sample, evsel, session, thread);
>  
>  	session->hists.stats.total_period += sample->period;
> @@ -1075,6 +1083,7 @@ static const struct option options[] = {
>  	OPT_CALLBACK('f', "fields", NULL, "str",
>  		     "comma separated output fields prepend with 'type:'. Valid types: hw,sw,trace,raw. Fields: comm,tid,pid,time,cpu,event,trace,ip,sym,dso,addr",
>  		     parse_output_fields),
> +	OPT_STRING('c', "cpu", &cpu_list, "cpu", "list of cpus to profile"),
>  
>  	OPT_END()
>  };
> @@ -1255,6 +1264,38 @@ int cmd_script(int argc, const char **ar
>  	if (session == NULL)
>  		return -ENOMEM;
>  
> +	if (cpu_list) {
> +		struct cpu_map *map;
> +
> +		for (i = 0; i < PERF_TYPE_MAX; ++i) {
> +			struct perf_evsel *evsel;
> +
> +			evsel = perf_session__find_first_evtype(session, i);
> +			if (!evsel)
> +				continue;
> +
> +			if (!(evsel->attr.sample_type & PERF_SAMPLE_CPU)) {
> +				pr_err("File does not contain CPU events. "
> +				       "Remove -c option to proceed.\n");
> +				return -1;
> +			}
> +		}
> +
> +		map = cpu_map__new(cpu_list);
> +
> +		for (i = 0; i < map->nr; i++) {
> +			int cpu = map->map[i];
> +
> +			if (cpu >= MAX_NR_CPUS) {
> +				pr_err("Requested CPU %d too large. "
> +				       "Consider raising MAX_NR_CPUS\n", cpu);
> +				return -1;
> +			}
> +
> +			set_bit(cpu, cpu_bitmap);
> +		}
> +	}
> +
>  	if (!no_callchain)
>  		symbol_conf.use_callchain = true;
>  	else
> Index: linux-2.6-tip/tools/perf/Documentation/perf-annotate.txt
> ===================================================================
> --- linux-2.6-tip.orig/tools/perf/Documentation/perf-annotate.txt	2011-06-30 11:35:17.768583314 +1000
> +++ linux-2.6-tip/tools/perf/Documentation/perf-annotate.txt	2011-06-30 11:35:19.618616362 +1000
> @@ -66,6 +66,12 @@ OPTIONS
>  	used. This interfaces starts by centering on the line with more
>  	samples, TAB/UNTAB cycles through the lines with more samples.
>  
> +-c::
> +--cpu:: Only report samples for the list of CPUs provided. Multiple CPUs can
> +	be provided as a comma-separated list with no space: 0,1. Ranges of
> +	CPUs are specified with -: 0-2. Default is to report samples on all
> +	CPUs.
> +
>  SEE ALSO
>  --------
>  linkperf:perf-record[1], linkperf:perf-report[1]
> Index: linux-2.6-tip/tools/perf/Documentation/perf-report.txt
> ===================================================================
> --- linux-2.6-tip.orig/tools/perf/Documentation/perf-report.txt	2011-06-30 11:35:17.768583314 +1000
> +++ linux-2.6-tip/tools/perf/Documentation/perf-report.txt	2011-06-30 11:35:19.618616362 +1000
> @@ -119,6 +119,12 @@ OPTIONS
>  --symfs=<directory>::
>          Look for files with symbols relative to this directory.
>  
> +-c::
> +--cpu:: Only report samples for the list of CPUs provided. Multiple CPUs can
> +	be provided as a comma-separated list with no space: 0,1. Ranges of
> +	CPUs are specified with -: 0-2. Default is to report samples on all
> +	CPUs.
> +
>  SEE ALSO
>  --------
>  linkperf:perf-stat[1]
> Index: linux-2.6-tip/tools/perf/Documentation/perf-script.txt
> ===================================================================
> --- linux-2.6-tip.orig/tools/perf/Documentation/perf-script.txt	2011-06-30 11:35:17.768583314 +1000
> +++ linux-2.6-tip/tools/perf/Documentation/perf-script.txt	2011-06-30 11:35:19.618616362 +1000
> @@ -182,6 +182,12 @@ OPTIONS
>  --hide-call-graph::
>          When printing symbols do not display call chain.
>  
> +-c::
> +--cpu:: Only report samples for the list of CPUs provided. Multiple CPUs can
> +	be provided as a comma-separated list with no space: 0,1. Ranges of
> +	CPUs are specified with -: 0-2. Default is to report samples on all
> +	CPUs.
> +
>  SEE ALSO
>  --------
>  linkperf:perf-record[1], linkperf:perf-script-perl[1],
>