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| author |   Jin Yao <yao.jin@linux.intel.com> | 2019-11-07 15:47:17 +0800 |
|---|---|---|
| committer |   Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-11-07 10:14:48 -0300 |
| commit | 6f7164fa231a5f360e576593c547bea7dc56ddbc (patch) | |
| tree | b8164ed1ea3e65aa866310d447a760f42350e08c /tools/perf/Documentation/perf-report.txt | |
| parent | perf hist: Support block formats with compare/sort/display (diff) | |
| download | linux-dev-6f7164fa231a5f360e576593c547bea7dc56ddbc.tar.xz linux-dev-6f7164fa231a5f360e576593c547bea7dc56ddbc.zip | |
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>
Diffstat (limited to 'tools/perf/Documentation/perf-report.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-report.txt | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt index 7315f155803f..8dbe2119686a 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 |