[tip: perf/core] perf report: Sort by sampled cycles percent per block for stdio

From: tip-bot2 for Jin Yao
Date: Tue Nov 12 2019 - 06:18:11 EST

The following commit has been merged into the perf/core branch of tip:

Commit-ID: 6f7164fa231a5f360e576593c547bea7dc56ddbc
Gitweb: https://git.kernel.org/tip/6f7164fa231a5f360e576593c547bea7dc56ddbc
Author: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
AuthorDate: Thu, 07 Nov 2019 15:47:17 +08:00
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitterDate: Thu, 07 Nov 2019 10:14:48 -03:00

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@xxxxxxxxxxxxxxx>
Reviewed-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Jin Yao <yao.jin@xxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lore.kernel.org/lkml/20191107074719.26139-6-yao.jin@xxxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-report.txt | 11 ++++++-
tools/perf/builtin-report.c | 44 +++++++++++++++++++++--
tools/perf/ui/stdio/hist.c | 22 ++++++++++++-
tools/perf/util/block-info.c | 17 +++++++++-
tools/perf/util/block-info.h | 4 ++-
tools/perf/util/symbol_conf.h | 1 +-
6 files changed, 96 insertions(+), 3 deletions(-)

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index 7315f15..8dbe211 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/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
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index bc15b9d..992b18b 100644
--- a/tools/perf/builtin-report.c
+++ b/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;
diff --git a/tools/perf/ui/stdio/hist.c b/tools/perf/ui/stdio/hist.c
index 5365606..655ef77 100644
--- a/tools/perf/ui/stdio/hist.c
+++ b/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);
diff --git a/tools/perf/util/block-info.c b/tools/perf/util/block-info.c
index 4a7bac9..ba89175 100644
--- a/tools/perf/util/block-info.c
+++ b/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;
+}
diff --git a/tools/perf/util/block-info.h b/tools/perf/util/block-info.h
index b526658..8309297 100644
--- a/tools/perf/util/block-info.h
+++ b/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 */
diff --git a/tools/perf/util/symbol_conf.h b/tools/perf/util/symbol_conf.h
index e688078..10f1ec3 100644
--- a/tools/perf/util/symbol_conf.h
+++ b/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,