summaryrefslogtreecommitdiff
path: root/tools/perf/Documentation
diff options
context:
space:
mode:
authorHagen Paul Pfeifer <hagen@jauu.net>2020-02-04 18:37:09 +0100
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-03-27 10:38:47 -0300
commit26567ed79d13ec54b2c5661ce8a07fd149a23a9b (patch)
tree786cda16b9c9dc1101db527e6a67a14477d7e71b /tools/perf/Documentation
parent26cec7480e7edaa9dead4912055078b98c1d192e (diff)
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>
Diffstat (limited to 'tools/perf/Documentation')
-rw-r--r--tools/perf/Documentation/perf-script.txt3
1 files changed, 3 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
index db6a36aac47e..4af255bb0977 100644
--- a/tools/perf/Documentation/perf-script.txt
+++ b/tools/perf/Documentation/perf-script.txt
@@ -390,6 +390,9 @@ include::itrace.txt[]
--reltime::
Print time stamps relative to trace start.
+--deltatime::
+ Print time stamps relative to previous event.
+
--per-event-dump::
Create per event files with a "perf.data.EVENT.dump" name instead of
printing to stdout, useful, for instance, for generating flamegraphs.