Hey all, I recorded a perf data file using
perf record --call-graph dwarf kwrite <some large file>
when I report it I see backtraces pointing to the user space code:
perf report --stdio -g graph --no-children
16.36% kwrite libKF5TextEditor.so.5.13.0 [.]
QArrayData::data
|
---QArrayData::data
|
|--15.46%-- QTypedArrayData<unsigned short>::data
but when I run perf script, I do not see _any_ backtraces into user space.
perf script -F comm,tid,time,event,ip,sym,trace,period
:4898 4898 17486.943365: 1 cycles:
25f83a native_write_msr_safe
234f8a __intel_pmu_enable_all
235010 intel_pmu_enable_all
22e1ec x86_pmu_enable
356fb7 perf_pmu_enable.part.53
35824d perf_event_context_sched_in.isra.64
358e0b perf_event_exec
3e8c93 setup_new_exec
439a9f load_elf_binary
3e7f48 search_binary_handler
3e89cf do_execveat_common.isra.15
3e8e4a sys_execve
78b895 return_from_execve
kwrite 4898 17486.943893: 1 cycles:
kwrite 4898 17486.944211: 1 cycles:
...
kwrite 4898 17486.953664: 461703 cycles:
kwrite 4898 17486.953838: 490150 cycles:
78d4c0 page_fault
kwrite 4898 17486.954009: 516694 cycles:
...
kwrite 4898 17510.765568: 766937 cycles:
78979b down_write
39bd82 unlink_file_vma
3944d0 free_pgtables
39eef6 exit_mmap
275d45 mmput
27b514 do_exit
27bdfb do_group_exit
27be84 [unknown]
78b56e system_call
So it looks to me as if only kernel-space call stacks are unwound in perf
script. Is there a magic switch that I'm missing to get user-space stacks
unwound? Note I'm using perf 4.1.0 on a Linux 4.1.2 system.
Thanks
--
Milian Wolff
[email protected]
http://milianw.de
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