perf script: Introduce --deltatime option
For some kind of analysis a deltatime output is more human friendly and
reduce the cognitive load for further analysis.
The following output demonstrate the new option "deltatime": calculate
the time difference in relation to the previous event.
$ perf script --deltatime
test 2525 [001] 0.000000: sdt_libev:ev_add: (5635e72a5ebd)
test 2525 [001] 0.000091: sdt_libev:epoll_wait_enter: (5635e72a76a9)
test 2525 [001] 1.000051: sdt_libev:epoll_wait_return: (5635e72a772e) arg1=1
test 2525 [001] 0.000685: sdt_libev:ev_add: (5635e72a5ebd)
test 2525 [001] 0.000048: sdt_libev:epoll_wait_enter: (5635e72a76a9)
test 2525 [001] 1.000104: sdt_libev:epoll_wait_return: (5635e72a772e) arg1=1
test 2525 [001] 0.003895: sdt_libev:epoll_wait_enter: (5635e72a76a9)
test 2525 [001] 0.996034: sdt_libev:epoll_wait_return: (5635e72a772e) arg1=1
test 2525 [001] 0.000058: sdt_libev:epoll_wait_enter: (5635e72a76a9)
test 2525 [001] 1.000004: sdt_libev:epoll_wait_return: (5635e72a772e) arg1=1
test 2525 [001] 0.000064: sdt_libev:epoll_wait_enter: (5635e72a76a9)
test 2525 [001] 0.999934: sdt_libev:epoll_wait_return: (5635e72a772e) arg1=1
test 2525 [001] 0.000056: sdt_libev:epoll_wait_enter: (5635e72a76a9)
test 2525 [001] 0.999930: sdt_libev:epoll_wait_return: (5635e72a772e) arg1=1
Committer testing:
So go from default output to --reltime and then this new --deltatime, to
contrast the various timestamp presentation modes for a random perf.data file I
had laying around:
[root@five ~]# perf script --reltime | head
perf 442394 [000] 0.000000: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [000] 0.000002: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [000] 0.000004: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [000] 0.000006: 128 cycles: ffffffff972415a1 perf_event_update_userpage+0x1 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [000] 0.000009: 2597 cycles: ffffffff97463785 cap_task_setscheduler+0x5 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 0.000036: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 0.000038: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 0.000040: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 0.000041: 224 cycles: ffffffff9700a53a perf_ibs_handle_irq+0x1da (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 0.000044: 4439 cycles: ffffffff97120d85 put_prev_entity+0x45 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
[root@five ~]# perf script --deltatime | head
perf 442394 [000] 0.000000: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [000] 0.000002: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [000] 0.000001: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [000] 0.000001: 128 cycles: ffffffff972415a1 perf_event_update_userpage+0x1 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [000] 0.000002: 2597 cycles: ffffffff97463785 cap_task_setscheduler+0x5 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 0.000027: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 0.000002: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 0.000001: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 0.000001: 224 cycles: ffffffff9700a53a perf_ibs_handle_irq+0x1da (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 0.000002: 4439 cycles: ffffffff97120d85 put_prev_entity+0x45 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
[root@five ~]# perf script | head
perf 442394 [000] 7600.157861: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [000] 7600.157864: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [000] 7600.157866: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [000] 7600.157867: 128 cycles: ffffffff972415a1 perf_event_update_userpage+0x1 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [000] 7600.157870: 2597 cycles: ffffffff97463785 cap_task_setscheduler+0x5 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 7600.157897: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 7600.157900: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 7600.157901: 16 cycles: ffffffff9706e544 native_write_msr+0x4 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 7600.157903: 224 cycles: ffffffff9700a53a perf_ibs_handle_irq+0x1da (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
perf 442394 [001] 7600.157906: 4439 cycles: ffffffff97120d85 put_prev_entity+0x45 (/usr/lib/debug/lib/modules/5.5.10-200.fc31.x86_64/vmlinux)
[root@five ~]#
Andi suggested we better implement it as a new field, i.e. -F deltatime, like:
[root@five ~]# perf script -F deltatime
Invalid field requested.
Usage: perf script [<options>]
or: perf script [<options>] record <script> [<record-options>] <command>
or: perf script [<options>] report <script> [script-args]
or: perf script [<options>] <script> [<record-options>] <command>
or: perf script [<options>] <top-script> [script-args]
-F, --fields <str> comma separated output fields prepend with 'type:'. +field to add and -field to remove.Valid types: hw,sw,trace,raw,synth. Fields: comm,tid,pid,time,cpu,event,trace,ip,sym,dso,addr,symoff,srcline,period,iregs,uregs,brstack,brstacksym,flags,bpf-output,brstackinsn,brstackoff,callindent,insn,insnlen,synth,phys_addr,metric,misc,ipc
[root@five ~]#
I.e. we have -F for maximum flexibility:
[root@five ~]# perf script -F comm,pid,cpu,time | head
perf 442394 [000] 7600.157861:
perf 442394 [000] 7600.157864:
perf 442394 [000] 7600.157866:
perf 442394 [000] 7600.157867:
perf 442394 [000] 7600.157870:
perf 442394 [001] 7600.157897:
perf 442394 [001] 7600.157900:
perf 442394 [001] 7600.157901:
perf 442394 [001] 7600.157903:
perf 442394 [001] 7600.157906:
[root@five ~]#
But since we already have --reltime, having --deltatime, documented one after
the other is sensible.
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20200204173709.489161-1-hagen@jauu.net
[ Added 'perf script' man page entry for --deltatime ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Hagen Paul Pfeifer
Arnaldo Carvalho de Melo
parent
26cec7480e
commit
26567ed79d
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@ -390,6 +390,9 @@ include::itrace.txt[]
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--reltime::
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Print time stamps relative to trace start.
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--deltatime::
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Print time stamps relative to previous event.
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--per-event-dump::
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Create per event files with a "perf.data.EVENT.dump" name instead of
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printing to stdout, useful, for instance, for generating flamegraphs.
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@ -63,7 +63,9 @@
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static char const *script_name;
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static char const *generate_script_lang;
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static bool reltime;
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static bool deltatime;
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static u64 initial_time;
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static u64 previous_time;
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static bool debug_mode;
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static u64 last_timestamp;
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static u64 nr_unordered;
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@ -704,6 +706,13 @@ static int perf_sample__fprintf_start(struct perf_sample *sample,
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if (!initial_time)
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initial_time = sample->time;
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t = sample->time - initial_time;
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} else if (deltatime) {
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if (previous_time)
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t = sample->time - previous_time;
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else {
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t = 0;
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}
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previous_time = sample->time;
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}
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nsecs = t;
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secs = nsecs / NSEC_PER_SEC;
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@ -3555,6 +3564,7 @@ int cmd_script(int argc, const char **argv)
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"anything beyond the specified depth will be ignored. "
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"Default: kernel.perf_event_max_stack or " __stringify(PERF_MAX_STACK_DEPTH)),
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OPT_BOOLEAN(0, "reltime", &reltime, "Show time stamps relative to start"),
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OPT_BOOLEAN(0, "deltatime", &deltatime, "Show time stamps relative to previous event"),
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OPT_BOOLEAN('I', "show-info", &show_full_info,
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"display extended information from perf.data file"),
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OPT_BOOLEAN('\0', "show-kernel-path", &symbol_conf.show_kernel_path,
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@ -3651,6 +3661,13 @@ int cmd_script(int argc, const char **argv)
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}
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}
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if (reltime && deltatime) {
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fprintf(stderr,
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"reltime and deltatime - the two don't get along well. "
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"Please limit to --reltime or --deltatime.\n");
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return -1;
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}
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if (itrace_synth_opts.callchain &&
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itrace_synth_opts.callchain_sz > scripting_max_stack)
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scripting_max_stack = itrace_synth_opts.callchain_sz;
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