kernel/linux.git/tools/perf/Documentation/perf-diff.txt, branch v6.6.131

perf tools: Make quiet mode consistent between tools

2022-10-27T19:37:26+00:00

Use the global quiet variable everywhere so that all tools hide warnings in quiet mode and update the documentation to reflect this. 'perf probe' claimed that errors are not printed in quiet mode but I don't see this so remove it from the docs. Signed-off-by: James Clark Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20221018094137.783081-3-james.clark@arm.com Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Support hot streams comparison

2020-10-14T16:34:48+00:00

This patch enables perf-diff with "--stream" option. "--stream": Enable hot streams comparison Now let's see example. perf record -b ... Generate perf.data.old with branch data perf record -b ... Generate perf.data with branch data perf diff --stream [ Matched hot streams ] hot chain pair 1: cycles: 1, hits: 27.77% cycles: 1, hits: 9.24% --------------------------- -------------------------- main div.c:39 main div.c:39 main div.c:44 main div.c:44 hot chain pair 2: cycles: 34, hits: 20.06% cycles: 27, hits: 16.98% --------------------------- -------------------------- __random_r random_r.c:360 __random_r random_r.c:360 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:380 __random_r random_r.c:380 __random_r random_r.c:357 __random_r random_r.c:357 __random random.c:293 __random random.c:293 __random random.c:293 __random random.c:293 __random random.c:291 __random random.c:291 __random random.c:291 __random random.c:291 __random random.c:291 __random random.c:291 __random random.c:288 __random random.c:288 rand rand.c:27 rand rand.c:27 rand rand.c:26 rand rand.c:26 rand@plt rand@plt rand@plt rand@plt compute_flag div.c:25 compute_flag div.c:25 compute_flag div.c:22 compute_flag div.c:22 main div.c:40 main div.c:40 main div.c:40 main div.c:40 main div.c:39 main div.c:39 hot chain pair 3: cycles: 9, hits: 4.48% cycles: 6, hits: 4.51% --------------------------- -------------------------- __random_r random_r.c:360 __random_r random_r.c:360 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:380 __random_r random_r.c:380 [ Hot streams in old perf data only ] hot chain 1: cycles: 18, hits: 6.75% -------------------------- __random_r random_r.c:360 __random_r random_r.c:388 __random_r random_r.c:388 __random_r random_r.c:380 __random_r random_r.c:357 __random random.c:293 __random random.c:293 __random random.c:291 __random random.c:291 __random random.c:291 __random random.c:288 rand rand.c:27 rand rand.c:26 rand@plt rand@plt compute_flag div.c:25 compute_flag div.c:22 main div.c:40 hot chain 2: cycles: 29, hits: 2.78% -------------------------- compute_flag div.c:22 main div.c:40 main div.c:40 main div.c:39 [ Hot streams in new perf data only ] hot chain 1: cycles: 4, hits: 4.54% -------------------------- main div.c:42 compute_flag div.c:28 hot chain 2: cycles: 5, hits: 3.51% -------------------------- main div.c:39 main div.c:44 main div.c:42 compute_flag div.c:28 Signed-off-by: Jin Yao Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20201009022845.13141-8-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Report noisy for cycles diff

2019-10-11T13:57:00+00:00

This patch prints the stddev and hist for the cycles diff of program block. It can help us to understand if the cycles is noisy or not. This patch is inspired by Andi Kleen's patch: https://lwn.net/Articles/600471/ We create new option '--cycles-hist'. Example: perf record -b ./div perf record -b ./div perf diff -c cycles # Baseline [Program Block Range] Cycles Diff Shared Object Symbol # ........ .......................................................... .... ................. ............................ # 46.72% [div.c:40 -> div.c:40] 0 div [.] main 46.72% [div.c:42 -> div.c:44] 0 div [.] main 46.72% [div.c:42 -> div.c:39] 0 div [.] main 20.54% [random_r.c:357 -> random_r.c:394] 1 libc-2.27.so [.] __random_r 20.54% [random_r.c:357 -> random_r.c:380] 0 libc-2.27.so [.] __random_r 20.54% [random_r.c:388 -> random_r.c:388] 0 libc-2.27.so [.] __random_r 20.54% [random_r.c:388 -> random_r.c:391] 0 libc-2.27.so [.] __random_r 17.04% [random.c:288 -> random.c:291] 0 libc-2.27.so [.] __random 17.04% [random.c:291 -> random.c:291] 0 libc-2.27.so [.] __random 17.04% [random.c:293 -> random.c:293] 0 libc-2.27.so [.] __random 17.04% [random.c:295 -> random.c:295] 0 libc-2.27.so [.] __random 17.04% [random.c:295 -> random.c:295] 0 libc-2.27.so [.] __random 17.04% [random.c:298 -> random.c:298] 0 libc-2.27.so [.] __random 8.40% [div.c:22 -> div.c:25] 0 div [.] compute_flag 8.40% [div.c:27 -> div.c:28] 0 div [.] compute_flag 5.14% [rand.c:26 -> rand.c:27] 0 libc-2.27.so [.] rand 5.14% [rand.c:28 -> rand.c:28] 0 libc-2.27.so [.] rand 2.15% [rand@plt+0 -> rand@plt+0] 0 div [.] rand@plt 0.00% [kernel.kallsyms] [k] __x86_indirect_thunk_rax 0.00% [do_mmap+714 -> do_mmap+732] -10 [kernel.kallsyms] [k] do_mmap 0.00% [do_mmap+737 -> do_mmap+765] 1 [kernel.kallsyms] [k] do_mmap 0.00% [do_mmap+262 -> do_mmap+299] 0 [kernel.kallsyms] [k] do_mmap 0.00% [__x86_indirect_thunk_r15+0 -> __x86_indirect_thunk_r15+0] 7 [kernel.kallsyms] [k] __x86_indirect_thunk_r15 0.00% [native_sched_clock+0 -> native_sched_clock+119] -1 [kernel.kallsyms] [k] native_sched_clock 0.00% [native_write_msr+0 -> native_write_msr+16] -13 [kernel.kallsyms] [k] native_write_msr When we enable the option '--cycles-hist', the output is perf diff -c cycles --cycles-hist # Baseline [Program Block Range] Cycles Diff stddev/Hist Shared Object Symbol # ........ .......................................................... .... ................. ................. ............................ # 46.72% [div.c:40 -> div.c:40] 0 ± 37.8% ▁█▁▁██▁█ div [.] main 46.72% [div.c:42 -> div.c:44] 0 ± 49.4% ▁▁▂█▂▂▂▂ div [.] main 46.72% [div.c:42 -> div.c:39] 0 ± 24.1% ▃█▂▄▁▃▂▁ div [.] main 20.54% [random_r.c:357 -> random_r.c:394] 1 ± 33.5% ▅▂▁█▃▁▂▁ libc-2.27.so [.] __random_r 20.54% [random_r.c:357 -> random_r.c:380] 0 ± 39.4% ▁▁█▁██▅▁ libc-2.27.so [.] __random_r 20.54% [random_r.c:388 -> random_r.c:388] 0 libc-2.27.so [.] __random_r 20.54% [random_r.c:388 -> random_r.c:391] 0 ± 41.2% ▁▃▁▂█▄▃▁ libc-2.27.so [.] __random_r 17.04% [random.c:288 -> random.c:291] 0 ± 48.8% ▁▁▁▁███▁ libc-2.27.so [.] __random 17.04% [random.c:291 -> random.c:291] 0 ±100.0% ▁█▁▁▁▁▁▁ libc-2.27.so [.] __random 17.04% [random.c:293 -> random.c:293] 0 ±100.0% ▁█▁▁▁▁▁▁ libc-2.27.so [.] __random 17.04% [random.c:295 -> random.c:295] 0 ±100.0% ▁█▁▁▁▁▁▁ libc-2.27.so [.] __random 17.04% [random.c:295 -> random.c:295] 0 libc-2.27.so [.] __random 17.04% [random.c:298 -> random.c:298] 0 ± 75.6% ▃█▁▁▁▁▁▁ libc-2.27.so [.] __random 8.40% [div.c:22 -> div.c:25] 0 ± 42.1% ▁▃▁▁███▁ div [.] compute_flag 8.40% [div.c:27 -> div.c:28] 0 ± 41.8% ██▁▁▄▁▁▄ div [.] compute_flag 5.14% [rand.c:26 -> rand.c:27] 0 ± 37.8% ▁▁▁████▁ libc-2.27.so [.] rand 5.14% [rand.c:28 -> rand.c:28] 0 libc-2.27.so [.] rand 2.15% [rand@plt+0 -> rand@plt+0] 0 div [.] rand@plt 0.00% [kernel.kallsyms] [k] __x86_indirect_thunk_rax 0.00% [do_mmap+714 -> do_mmap+732] -10 [kernel.kallsyms] [k] do_mmap 0.00% [do_mmap+737 -> do_mmap+765] 1 [kernel.kallsyms] [k] do_mmap 0.00% [do_mmap+262 -> do_mmap+299] 0 [kernel.kallsyms] [k] do_mmap 0.00% [__x86_indirect_thunk_r15+0 -> __x86_indirect_thunk_r15+0] 7 [kernel.kallsyms] [k] __x86_indirect_thunk_r15 0.00% [native_sched_clock+0 -> native_sched_clock+119] -1 ± 38.5% ▄█▁ [kernel.kallsyms] [k] native_sched_clock 0.00% [native_write_msr+0 -> native_write_msr+16] -13 ± 47.1% ▁█▇▃▁▁ [kernel.kallsyms] [k] native_write_msr v8: --- Rebase to perf/core branch v7: --- 1. v6 got Jiri's ACK. 2. Rebase to latest perf/core branch. v6: --- 1. Jiri provides better code for using data__hpp_register() in ui_init(). Use this code in v6. v5: --- 1. Refine the use of data__hpp_register() in ui_init() according to Jiri's suggestion. v4: --- 1. Rename the new option from '--noisy' to '--cycles-hist' 2. Remove the option '-n'. 3. Only update the spark value and stats when '--cycles-hist' is enabled. 4. Remove the code of printing '..'. v3: --- 1. Move the histogram to a separate column 2. Move the svals[] out of struct stats v2: --- Jiri got a compile error, CC builtin-diff.o builtin-diff.c: In function ‘compute_cycles_diff’: builtin-diff.c:712:10: error: taking the absolute value of unsigned type ‘u64’ {aka ‘long unsigned int’} has no effect [-Werror=absolute-value] 712 | labs(pair->block_info->cycles_spark[i] - | ^~~~ Because the result of u64 - u64 is still u64. Now we change the type of cycles_spark[] to s64. Signed-off-by: Jin Yao Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Kan Liang Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20190925011446.30678-1-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Documentation -c cycles option

2019-07-02T16:20:51+00:00

Documentation the new computation selection 'cycles'. v4: --- Change the column 'Block cycles diff [start:end]' to '[Program Block Range] Cycles Diff' Signed-off-by: Jin Yao Reviewed-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jin Yao Cc: Kan Liang Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1561713784-30533-8-git-send-email-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf time-utils: Add support for multiple explicit time intervals

2019-06-10T19:20:13+00:00

Currently only a single explicit time range is accepted. Add support for multiple ranges separated by spaces, which requires the string to be quoted. Update the time utils test accordingly. Signed-off-by: Adrian Hunter Cc: Jin Yao Cc: Jiri Olsa Link: http://lkml.kernel.org/r/20190604130017.31207-20-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf time-utils: Fix --time documentation

2019-06-10T19:20:12+00:00

Correct some punctuation and spelling and correct the format to show that the time resolution is nanoseconds not microseconds. Signed-off-by: Adrian Hunter Cc: Jin Yao Cc: Jiri Olsa Link: http://lkml.kernel.org/r/20190604130017.31207-16-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Support --pid/--tid filter options

2019-03-06T21:06:16+00:00

Using the existing symbol_conf.pid_list_str and symbol_conf.tid_list_str logic. For example: perf diff --tid 13965 It'll only diff the samples for thread 13965. Signed-off-by: Jin Yao Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jin Yao Cc: Kan Liang Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1551791143-10334-4-git-send-email-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Support --cpu filter option

2019-03-06T21:05:21+00:00

To improve 'perf diff', implement a --cpu filter option. 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. For example, perf diff --cpu 0,1 It only diff the samples for CPU0 and CPU1. Signed-off-by: Jin Yao Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jin Yao Cc: Kan Liang Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1551791143-10334-3-git-send-email-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Support --time filter option

2019-03-06T21:03:23+00:00

To improve 'perf diff', implement a --time filter option to diff the samples within given time window. It supports time percent with multiple time ranges. The time string format is 'a%/n,b%/m,...' or 'a%-b%,c%-%d,...'. For example: Select the second 10% time slice to diff: perf diff --time 10%/2 Select from 0% to 10% time slice to diff: perf diff --time 0%-10% Select the first and the second 10% time slices to diff: perf diff --time 10%/1,10%/2 Select from 0% to 10% and 30% to 40% slices to diff: perf diff --time 0%-10%,30%-40% It also supports analysing samples within a given time window ,. Times have the format seconds.microseconds. If 'start' is not given (i.e., time string is ',x.y') then analysis starts at the beginning of the file. If the stop time is not given (i.e, time string is 'x.y,') then analysis goes to end of file. Time string is 'a1.b1,c1.d1:a2.b2,c2.d2'. Use ':' to separate timestamps for different perf.data files. For example, we get the timestamp information from perf script. perf script -i perf.data.old mgen 13940 [000] 3946.361400: ... perf script -i perf.data mgen 13940 [000] 3971.150589 ... perf diff --time 3946.361400,:3971.150589, It analyzes the perf.data.old from the timestamp 3946.361400 to the end of perf.data.old and analyzes the perf.data from the timestamp 3971.150589 to the end of perf.data. v4: --- Update abstime_str_dup(), let it return error if strdup is failed, and update __cmd_diff() accordingly. Signed-off-by: Jin Yao Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jin Yao Cc: Kan Liang Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1551791143-10334-2-git-send-email-yao.jin@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Add -q/--quiet option

2017-02-20T14:47:08+00:00

The -q/--quiet option is to suppress any message. Sometimes users just want to see the numbers and it can be used for that case. Committer notes: Before: # perf diff | head -10 Failed to open /tmp/perf-6678.map, continuing without symbols Failed to open /tmp/perf-6678.map, continuing without symbols Failed to open /tmp/perf-2646.map, continuing without symbols # Event 'cycles' # # Baseline Delta Abs Shared Object Symbol # ........ ......... .......................... ............................................ # 5.36% -1.76% [kernel.vmlinux] [k] intel_idle 2.80% +1.48% firefox [.] 0x00000000000101fe 57.12% -1.25% libxul.so [.] 0x00000000009bea92 1.36% -1.11% [kernel.vmlinux] [k] __schedule 4.26% -1.00% perf-6678.map [.] 0x00007fac4b0e9320 After: # perf diff -q | head -10 5.36% -1.76% [kernel.vmlinux] [k] intel_idle 2.80% +1.48% firefox [.] 0x00000000000101fe 57.12% -1.25% libxul.so [.] 0x00000000009bea92 1.36% -1.11% [kernel.vmlinux] [k] __schedule 4.26% -1.00% perf-6678.map [.] 0x00007fac4b0e9320 1.86% +0.95% [kernel.vmlinux] [k] update_blocked_averages 0.80% -0.70% [kernel.vmlinux] [k] native_sched_clock 0.74% -0.58% [kernel.vmlinux] [k] native_write_msr 0.76% -0.56% qemu-system-x86_64 [.] 0x00000000002395c0 +0.54% libpulsecommon-10.0.so [.] 0x000000000002d91b # Signed-off-by: Namhyung Kim Suggested-and-Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Peter Zijlstra Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170217081742.17417-5-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo