kernel/tools/perf/Documentation/perf-diff.txt, branch linux-5.1.y

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

2019-03-06T21:06:16Z

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

2019-03-06T21:05:21Z

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

2019-03-06T21:03:23Z

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

2017-02-20T14:47:08Z

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

perf diff: Change default setting to "delta-abs"

2017-02-13T17:29:38Z

The "delta-abs" compute method will show most changed entries on top. So users can easily see how much effect between the data. Note that it also changes the default of -o option to 1 in order to apply the compute method. To see original-style (sorted by baseline) use -o 0 option. Signed-off-by: Namhyung Kim Cc: Jiri Olsa Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20170210161856.18422-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Add diff.compute config option

2017-02-13T17:29:37Z

The diff.compute config variable is to set the default compute method of perf diff command (-c option). Possible values 'delta' (default), 'delta-abs', 'ratio' and 'wdiff'. Signed-off-by: Namhyung Kim Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Taeung Song Link: http://lkml.kernel.org/r/20170210073614.24584-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Add diff.order config option

2017-02-13T17:29:37Z

In many cases, I need to look at differences between two data so I often used the -o option to sort the result base on the difference first. It'd be nice to have a config option to set it by default. The diff.order config option is to set the default value of -o/--order option. Signed-off-by: Namhyung Kim Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Taeung Song Link: http://lkml.kernel.org/r/20170210073614.24584-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Add 'delta-abs' compute method

2017-02-13T17:29:36Z

The 'delta-abs' compute method is same as 'delta' but shows entries with bigger absolute delta first instead of sorting numerically. This is only useful together with -o option. Below is default output (-c delta): $ perf diff -o 1 -c delta | grep -v ^# | head 42.22% +4.97% [kernel.kallsyms] [k] cfb_imageblit 0.62% +1.23% [kernel.kallsyms] [k] mutex_lock +1.15% [kernel.kallsyms] [k] copy_user_generic_string 2.40% +0.95% [kernel.kallsyms] [k] bit_putcs 0.31% +0.79% [kernel.kallsyms] [k] link_path_walk +0.64% [kernel.kallsyms] [k] kmem_cache_alloc 0.00% +0.57% [kernel.kallsyms] [k] __rcu_read_unlock +0.45% [kernel.kallsyms] [k] alloc_set_pte 0.16% +0.45% [kernel.kallsyms] [k] menu_select +0.41% ld-2.24.so [.] do_lookup_x Now with 'delta-abs' it shows entries have bigger delta value either positive or negative. $ perf diff -o 1 -c delta-abs | grep -v ^# | head 42.22% +4.97% [kernel.kallsyms] [k] cfb_imageblit 12.72% -3.01% [kernel.kallsyms] [k] intel_idle 9.72% -1.31% [unknown] [.] 0x0000000000411343 0.62% +1.23% [kernel.kallsyms] [k] mutex_lock 2.40% +0.95% [kernel.kallsyms] [k] bit_putcs 0.31% +0.79% [kernel.kallsyms] [k] link_path_walk 1.35% -0.71% [kernel.kallsyms] [k] smp_call_function_single 0.00% +0.57% [kernel.kallsyms] [k] __rcu_read_unlock 0.16% +0.45% [kernel.kallsyms] [k] menu_select 0.72% -0.44% [kernel.kallsyms] [k] lookup_fast Signed-off-by: Namhyung Kim Cc: Jiri Olsa Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20170210073614.24584-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Make -f/--force option documentation consistent across tools

2016-03-30T14:14:08Z

Signed-off-by: Jiri Olsa Cc: Andi Kleen Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1458823940-24583-6-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Add kallsyms option

2015-03-24T16:01:54Z

Required for off-box analysis to convert kernel addresses. Signed-off-by: David Ahern Cc: Jiri Olsa Link: http://lkml.kernel.org/r/1427212317-7018-1-git-send-email-dsahern@gmail.com Signed-off-by: Arnaldo Carvalho de Melo