perf report: Sort by sampled cycles percent per block for stdio

It would be useful to support sorting for all blocks by the sampled
cycles percent per block. This is useful to concentrate on the globally
hottest blocks.

This patch implements a new option "--total-cycles" which sorts all
blocks by 'Sampled Cycles%'. The 'Sampled Cycles%' is the percent:

 percent = block sampled cycles aggregation / total sampled cycles

Note that, this patch only supports "--stdio" mode.

For example,

  # perf record -b ./div
  # perf report --total-cycles --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  # Total Lost Samples: 0
  #
  # Samples: 2M of event 'cycles'
  # Event count (approx.): 2753248
  #
  # Sampled Cycles%  Sampled Cycles  Avg Cycles%  Avg Cycles                             [Program Block Range]      Shared Object
  # ...............  ..............  ...........  ..........  ................................................  .................
  #
             26.04%            2.8M        0.40%          18                            [div.c:42 -> div.c:39]                div
             15.17%            1.2M        0.16%           7                [random_r.c:357 -> random_r.c:380]       libc-2.27.so
              5.11%          402.0K        0.04%           2                            [div.c:27 -> div.c:28]                div
              4.87%          381.6K        0.04%           2                    [random.c:288 -> random.c:291]       libc-2.27.so
              4.53%          381.0K        0.04%           2                            [div.c:40 -> div.c:40]                div
              3.85%          300.9K        0.02%           1                            [div.c:22 -> div.c:25]                div
              3.08%          241.1K        0.02%           1                          [rand.c:26 -> rand.c:27]       libc-2.27.so
              3.06%          240.0K        0.02%           1                    [random.c:291 -> random.c:291]       libc-2.27.so
              2.78%          215.7K        0.02%           1                    [random.c:298 -> random.c:298]       libc-2.27.so
              2.52%          198.3K        0.02%           1                    [random.c:293 -> random.c:293]       libc-2.27.so
              2.36%          184.8K        0.02%           1                          [rand.c:28 -> rand.c:28]       libc-2.27.so
              2.33%          180.5K        0.02%           1                    [random.c:295 -> random.c:295]       libc-2.27.so
              2.28%          176.7K        0.02%           1                    [random.c:295 -> random.c:295]       libc-2.27.so
              2.20%          168.8K        0.02%           1                        [rand@plt+0 -> rand@plt+0]                div
              1.98%          158.2K        0.02%           1                [random_r.c:388 -> random_r.c:388]       libc-2.27.so
              1.57%          123.3K        0.02%           1                            [div.c:42 -> div.c:44]                div
              1.44%          116.0K        0.42%          19                [random_r.c:357 -> random_r.c:394]       libc-2.27.so
              0.25%          182.5K        0.02%           1                [random_r.c:388 -> random_r.c:391]       libc-2.27.so
              0.00%              48        1.07%          48        [x86_pmu_enable+284 -> x86_pmu_enable+298]  [kernel.kallsyms]
              0.00%              74        1.64%          74             [vm_mmap_pgoff+0 -> vm_mmap_pgoff+92]  [kernel.kallsyms]
              0.00%              73        1.62%          73                         [vm_mmap+0 -> vm_mmap+48]  [kernel.kallsyms]
              0.00%              63        0.69%          31                       [up_write+0 -> up_write+34]  [kernel.kallsyms]
              0.00%              13        0.29%          13      [setup_arg_pages+396 -> setup_arg_pages+413]  [kernel.kallsyms]
              0.00%               3        0.07%           3      [setup_arg_pages+418 -> setup_arg_pages+450]  [kernel.kallsyms]
              0.00%             616        6.84%         308   [security_mmap_file+0 -> security_mmap_file+72]  [kernel.kallsyms]
              0.00%              23        0.51%          23  [security_mmap_file+77 -> security_mmap_file+87]  [kernel.kallsyms]
              0.00%               4        0.02%           1                  [sched_clock+0 -> sched_clock+4]  [kernel.kallsyms]
              0.00%               4        0.02%           1                 [sched_clock+9 -> sched_clock+12]  [kernel.kallsyms]
              0.00%               1        0.02%           1                [rcu_nmi_exit+0 -> rcu_nmi_exit+9]  [kernel.kallsyms]

Committer testing:

This should provide material for hours of endless joy, both from looking
for suspicious things in the implementation of this patch, such as the
top one:

  # Sampled Cycles%  Sampled Cycles  Avg Cycles%  Avg Cycles                          [Program Block Range]     Shared Object
              2.17%            1.7M        0.08%         607   [compiler.h:199 -> common.c:221]              [kernel.vmlinux]

As well from things that look legit:

  # Sampled Cycles%  Sampled Cycles  Avg Cycles%  Avg Cycles                          [Program Block Range]     Shared Object
              0.16%          123.0K        0.60%        4.7K   [nospec-branch.h:265 -> nospec-branch.h:278]  [kernel.vmlinux]

:-)

Very short system wide taken branches session:

  # perf record -h -b

   Usage: perf record [<options>] [<command>]
      or: perf record [<options>] -- <command> [<options>]

      -b, --branch-any      sample any taken branches

  #
  # perf record -b
  ^C[ perf record: Woken up 595 times to write data ]
  [ perf record: Captured and wrote 156.672 MB perf.data (196873 samples) ]

  #
  # perf evlist -v
  cycles: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD|BRANCH_STACK, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, branch_sample_type: ANY
  #
  # perf report --total-cycles --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  # Total Lost Samples: 0
  #
  # Samples: 6M of event 'cycles'
  # Event count (approx.): 6299936
  #
  # Sampled Cycles%  Sampled Cycles  Avg Cycles%  Avg Cycles                                                   [Program Block Range]         Shared Object
  # ...............  ..............  ...........  ..........  ......................................................................  ....................
  #
              2.17%            1.7M        0.08%         607                                        [compiler.h:199 -> common.c:221]      [kernel.vmlinux]
              1.75%            1.3M        8.34%       65.5K    [memset-vec-unaligned-erms.S:147 -> memset-vec-unaligned-erms.S:151]          libc-2.29.so
              0.72%          544.5K        0.03%         230                                      [entry_64.S:657 -> entry_64.S:662]      [kernel.vmlinux]
              0.56%          541.8K        0.09%         672                                        [compiler.h:199 -> common.c:300]      [kernel.vmlinux]
              0.39%          293.2K        0.01%         104                                    [list_debug.c:43 -> list_debug.c:61]      [kernel.vmlinux]
              0.36%          278.6K        0.03%         272                                    [entry_64.S:1289 -> entry_64.S:1308]      [kernel.vmlinux]
              0.30%          260.8K        0.07%         564                              [clear_page_64.S:47 -> clear_page_64.S:50]      [kernel.vmlinux]
              0.28%          215.3K        0.05%         369                                            [traps.c:623 -> traps.c:628]      [kernel.vmlinux]
              0.23%          178.1K        0.04%         278                                      [entry_64.S:271 -> entry_64.S:275]      [kernel.vmlinux]
              0.20%          152.6K        0.09%         706                                      [paravirt.c:177 -> paravirt.c:179]      [kernel.vmlinux]
              0.20%          155.8K        0.05%         373                                      [entry_64.S:153 -> entry_64.S:175]      [kernel.vmlinux]
              0.18%          136.6K        0.03%         222                                                [msr.h:105 -> msr.h:166]      [kernel.vmlinux]
              0.16%          123.0K        0.60%        4.7K                            [nospec-branch.h:265 -> nospec-branch.h:278]      [kernel.vmlinux]
              0.16%          118.3K        0.01%          44                                      [entry_64.S:632 -> entry_64.S:657]      [kernel.vmlinux]
              0.14%          104.5K        0.00%          28                                          [rwsem.c:1541 -> rwsem.c:1544]      [kernel.vmlinux]
              0.13%           99.2K        0.01%          53                                      [spinlock.c:150 -> spinlock.c:152]      [kernel.vmlinux]
              0.13%           95.5K        0.00%          35                                              [swap.c:456 -> swap.c:471]      [kernel.vmlinux]
              0.12%           96.2K        0.05%         407                              [copy_user_64.S:175 -> copy_user_64.S:209]      [kernel.vmlinux]
              0.11%           85.9K        0.00%          31                                        [swap.c:400 -> page-flags.h:188]      [kernel.vmlinux]
              0.10%           73.0K        0.01%          52                                          [paravirt.h:763 -> list.h:131]      [kernel.vmlinux]
              0.07%           56.2K        0.03%         214                                      [filemap.c:1524 -> filemap.c:1557]      [kernel.vmlinux]
              0.07%           54.2K        0.02%         145                                        [memory.c:1032 -> memory.c:1049]      [kernel.vmlinux]
              0.07%           50.3K        0.00%          39                                            [mmzone.c:49 -> mmzone.c:69]      [kernel.vmlinux]
              0.06%           48.3K        0.01%          40                                   [paravirt.h:768 -> page_alloc.c:3304]      [kernel.vmlinux]
              0.06%           46.7K        0.02%         155                                        [memory.c:1032 -> memory.c:1056]      [kernel.vmlinux]
              0.06%           46.9K        0.01%         103                                              [swap.c:867 -> swap.c:902]      [kernel.vmlinux]
              0.06%           47.8K        0.00%          34                                    [entry_64.S:1201 -> entry_64.S:1202]      [kernel.vmlinux]

 -----------------------------------------------------------

 v7:
 ---
 Use use_browser in report__browse_block_hists for supporting
 stdio and potential tui mode.

 v6:
 ---
 Create report__browse_block_hists in block-info.c (codes are
 moved from builtin-report.c). It's called from
 perf_evlist__tty_browse_hists.

 v5:
 ---
 1. Move all block functions to block-info.c

 2. Move the code of setting ms in block hist_entry to
    other patch.

 v4:
 ---
 1. Use new option '--total-cycles' to replace
    '-s total_cycles' in v3.

 2. Move block info collection out of block info
    printing.

 v3:
 ---
 1. Use common function block_info__process_sym to
    process the blocks per symbol.

 2. Remove the nasty hack for skipping calculation
    of column length

 3. Some minor cleanup

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20191107074719.26139-6-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-report.txt

@@ -525,6 +525,17 @@ include::itrace.txt[]
 	Configure time quantum for time sort key. Default 100ms.
 	Accepts s, us, ms, ns units.
 
+--total-cycles::
+	When --total-cycles is specified, it supports sorting for all blocks by
+	'Sampled Cycles%'. This is useful to concentrate on the globally hottest
+	blocks. In output, there are some new columns:
+
+	'Sampled Cycles%' - block sampled cycles aggregation / total sampled cycles
+	'Sampled Cycles'  - block sampled cycles aggregation
+	'Avg Cycles%'     - block average sampled cycles / sum of total block average
+			    sampled cycles
+	'Avg Cycles'      - block average sampled cycles
+
 include::callchain-overhead-calculation.txt[]
 
 SEE ALSO

tools/perf/builtin-report.c

@@ -51,6 +51,7 @@
 #include "util/util.h" // perf_tip()
 #include "ui/ui.h"
 #include "ui/progress.h"
+#include "util/block-info.h"
 
 #include <dlfcn.h>
 #include <errno.h>
@@ -96,10 +97,13 @@ struct report {
 	float			min_percent;
 	u64			nr_entries;
 	u64			queue_size;
+	u64			total_cycles;
 	int			socket_filter;
 	DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);
 	struct branch_type_stat	brtype_stat;
 	bool			symbol_ipc;
+	bool			total_cycles_mode;
+	struct block_report	*block_reports;
 };
 
 static int report__config(const char *var, const char *value, void *cb)
@@ -290,9 +294,10 @@ static int process_sample_event(struct perf_tool *tool,
 	if (al.map != NULL)
 		al.map->dso->hit = 1;
 
-	if (ui__has_annotation() || rep->symbol_ipc) {
+	if (ui__has_annotation() || rep->symbol_ipc || rep->total_cycles_mode) {
 		hist__account_cycles(sample->branch_stack, &al, sample,
-				     rep->nonany_branch_mode, NULL);
+				     rep->nonany_branch_mode,
+				     &rep->total_cycles);
 	}
 
 	ret = hist_entry_iter__add(&iter, &al, rep->max_stack, rep);
@@ -485,6 +490,7 @@ static int perf_evlist__tty_browse_hists(struct evlist *evlist,
 					 const char *help)
 {
 	struct evsel *pos;
+	int i = 0;
 
 	if (!quiet) {
 		fprintf(stdout, "#\n# Total Lost Samples: %" PRIu64 "\n#\n",
@@ -500,6 +506,13 @@ static int perf_evlist__tty_browse_hists(struct evlist *evlist,
 			continue;
 
 		hists__fprintf_nr_sample_events(hists, rep, evname, stdout);
+
+		if (rep->total_cycles_mode) {
+			report__browse_block_hists(&rep->block_reports[i++].hist,
+						   0, pos);
+			continue;
+		}
+
 		hists__fprintf(hists, !quiet, 0, 0, rep->min_percent, stdout,
 			       !(symbol_conf.use_callchain ||
 			         symbol_conf.show_branchflag_count));
@@ -925,6 +938,13 @@ static int __cmd_report(struct report *rep)
 
 	report__output_resort(rep);
 
+	if (rep->total_cycles_mode) {
+		rep->block_reports = block_info__create_report(session->evlist,
+							       rep->total_cycles);
+		if (!rep->block_reports)
+			return -1;
+	}
+
 	return report__browse_hists(rep);
 }
 
@@ -1209,6 +1229,8 @@ int cmd_report(int argc, const char **argv)
 		     "Set time quantum for time sort key (default 100ms)",
 		     parse_time_quantum),
 	OPTS_EVSWITCH(&report.evswitch),
+	OPT_BOOLEAN(0, "total-cycles", &report.total_cycles_mode,
+		    "Sort all blocks by 'Sampled Cycles%'"),
 	OPT_END()
 	};
 	struct perf_data data = {
@@ -1371,6 +1393,17 @@ repeat:
 		goto error;
 	}
 
+	if (report.total_cycles_mode) {
+		if (sort__mode != SORT_MODE__BRANCH)
+			report.total_cycles_mode = false;
+		else if (!report.use_stdio) {
+			pr_err("Error: --total-cycles can be only used together with --stdio\n");
+			goto error;
+		} else {
+			sort_order = "sym";
+		}
+	}
+
 	if (strcmp(input_name, "-") != 0)
 		setup_browser(true);
 	else
@@ -1421,7 +1454,8 @@ repeat:
 	 * so don't allocate extra space that won't be used in the stdio
 	 * implementation.
 	 */
-	if (ui__has_annotation() || report.symbol_ipc) {
+	if (ui__has_annotation() || report.symbol_ipc ||
+	    report.total_cycles_mode) {
 		ret = symbol__annotation_init();
 		if (ret < 0)
 			goto error;
@@ -1482,6 +1516,10 @@ error:
 		itrace_synth_opts__clear_time_range(&itrace_synth_opts);
 		zfree(&report.ptime_range);
 	}
+
+	if (report.block_reports)
+		zfree(&report.block_reports);
+
 	zstd_fini(&(session->zstd_data));
 	perf_session__delete(session);
 	return ret;

tools/perf/ui/stdio/hist.c

@@ -558,6 +558,25 @@ static int hist_entry__block_fprintf(struct hist_entry *he,
 	return ret;
 }
 
+static int hist_entry__individual_block_fprintf(struct hist_entry *he,
+						char *bf, size_t size,
+						FILE *fp)
+{
+	int ret = 0;
+
+	struct perf_hpp hpp = {
+		.buf		= bf,
+		.size		= size,
+		.skip		= false,
+	};
+
+	hist_entry__snprintf(he, &hpp);
+	if (!hpp.skip)
+		ret += fprintf(fp, "%s\n", bf);
+
+	return ret;
+}
+
 static int hist_entry__fprintf(struct hist_entry *he, size_t size,
 			       char *bf, size_t bfsz, FILE *fp,
 			       bool ignore_callchains)
@@ -580,6 +599,9 @@ static int hist_entry__fprintf(struct hist_entry *he, size_t size,
 	if (symbol_conf.report_block)
 		return hist_entry__block_fprintf(he, bf, size, fp);
 
+	if (symbol_conf.report_individual_block)
+		return hist_entry__individual_block_fprintf(he, bf, size, fp);
+
 	hist_entry__snprintf(he, &hpp);
 
 	ret = fprintf(fp, "%s\n", bf);

tools/perf/util/block-info.c

@@ -437,3 +437,20 @@ struct block_report *block_info__create_report(struct evlist *evlist,
 
 	return block_reports;
 }
+
+int report__browse_block_hists(struct block_hist *bh, float min_percent,
+			       struct evsel *evsel __maybe_unused)
+{
+	switch (use_browser) {
+	case 0:
+		symbol_conf.report_individual_block = true;
+		hists__fprintf(&bh->block_hists, true, 0, 0, min_percent,
+			       stdout, true);
+		hists__delete_entries(&bh->block_hists);
+		return 0;
+	default:
+		return -1;
+	}
+
+	return 0;
+}

tools/perf/util/block-info.h

@@ -7,6 +7,7 @@
 #include "hist.h"
 #include "symbol.h"
 #include "sort.h"
+#include "ui/ui.h"
 
 struct block_info {
 	struct symbol		*sym;
@@ -69,4 +70,7 @@ int block_info__process_sym(struct hist_entry *he, struct block_hist *bh,
 struct block_report *block_info__create_report(struct evlist *evlist,
 					       u64 total_cycles);
 
+int report__browse_block_hists(struct block_hist *bh, float min_percent,
+			       struct evsel *evsel);
+
 #endif /* __PERF_BLOCK_H */

tools/perf/util/symbol_conf.h

@@ -40,6 +40,7 @@ struct symbol_conf {
 			raw_trace,
 			report_hierarchy,
 			report_block,
+			report_individual_block,
 			inline_name,
 			disable_add2line_warn;
 	const char	*vmlinux_name,