2015-08-13 07:17:34

by Jiri Olsa

[permalink] [raw]
Subject: [PATCH] perf script: Initialize callchain_param.record_mode

On Wed, Jul 22, 2015 at 08:48:40PM +0200, Milian Wolff wrote:
> 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.

hi,
right you are.. does attached patch help?

thanks,
jirka


---
Milian Wolff reported non functional DWARF unwind under perf
script. The reason is that perf script does not properly configure
callchain_param.record_mode, which is needed by unwind code.

Stealing the code from report and leaving the place for
more initialization code in a hope we could merge it with
report__setup_sample_type one day.

Reported-by: Milian Wolff <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Jiri Olsa <[email protected]>
---
tools/perf/builtin-script.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 7b376d215e94..105332e950a9 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1561,6 +1561,22 @@ static int have_cmd(int argc, const char **argv)
return 0;
}

+static void script__setup_sample_type(struct perf_script *script)
+{
+ struct perf_session *session = script->session;
+ u64 sample_type = perf_evlist__combined_sample_type(session->evlist);
+
+ if (symbol_conf.use_callchain || symbol_conf.cumulate_callchain) {
+ if ((sample_type & PERF_SAMPLE_REGS_USER) &&
+ (sample_type & PERF_SAMPLE_STACK_USER))
+ callchain_param.record_mode = CALLCHAIN_DWARF;
+ else if (sample_type & PERF_SAMPLE_BRANCH_STACK)
+ callchain_param.record_mode = CALLCHAIN_LBR;
+ else
+ callchain_param.record_mode = CALLCHAIN_FP;
+ }
+}
+
int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
{
bool show_full_info = false;
@@ -1849,6 +1865,7 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
goto out_delete;

script.session = session;
+ script__setup_sample_type(&script);

session->itrace_synth_opts = &itrace_synth_opts;

--
2.4.3


2015-08-13 08:59:38

by Milian Wolff

[permalink] [raw]
Subject: Re: [PATCH] perf script: Initialize callchain_param.record_mode

On Thursday, August 13, 2015 09:17:24 AM Jiri Olsa wrote:
> On Wed, Jul 22, 2015 at 08:48:40PM +0200, Milian Wolff wrote:
> > 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.
>
> hi,
> right you are.. does attached patch help?

<snip>

Hey Jiri,

it works a treat!

Many thanks, much appreciated.

--
Milian Wolff | [email protected] | Software Engineer
KDAB (Deutschland) GmbH&Co KG, a KDAB Group company
Tel: +49-30-521325470
KDAB - The Qt Experts


Attachments:
smime.p7s (5.76 kB)

2015-08-17 13:47:56

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: Re: [PATCH] perf script: Initialize callchain_param.record_mode

Em Thu, Aug 13, 2015 at 10:53:36AM +0200, Milian Wolff escreveu:
> On Thursday, August 13, 2015 09:17:24 AM Jiri Olsa wrote:
> > right you are.. does attached patch help?
>
> <snip>
>
> Hey Jiri,
>
> it works a treat!
>
> Many thanks, much appreciated.

Adding a "Tested-by: Milian", Ok?

- Arnaldo

2015-08-17 13:56:27

by Milian Wolff

[permalink] [raw]
Subject: Re: [PATCH] perf script: Initialize callchain_param.record_mode

On Monday, August 17, 2015 10:47:50 AM CEST Arnaldo Carvalho de Melo wrote:
> Em Thu, Aug 13, 2015 at 10:53:36AM +0200, Milian Wolff escreveu:
> > On Thursday, August 13, 2015 09:17:24 AM Jiri Olsa wrote:
> > > right you are.. does attached patch help?
> >
> > <snip>
> >
> > Hey Jiri,
> >
> > it works a treat!
> >
> > Many thanks, much appreciated.
>
> Adding a "Tested-by: Milian", Ok?

Sure, please go ahead.

Thanks
--
Milian Wolff | [email protected] | Software Engineer
KDAB (Deutschland) GmbH&Co KG, a KDAB Group company
Tel: +49-30-521325470
KDAB - The Qt Experts

Subject: [tip:perf/core] perf script: Initialize callchain_param.record_mode

Commit-ID: 7322d6c98dd214252bd697f8dde64a3576977fab
Gitweb: http://git.kernel.org/tip/7322d6c98dd214252bd697f8dde64a3576977fab
Author: Jiri Olsa <[email protected]>
AuthorDate: Thu, 13 Aug 2015 09:17:24 +0200
Committer: Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Mon, 17 Aug 2015 10:48:39 -0300

perf script: Initialize callchain_param.record_mode

Milian Wolff reported non functional DWARF unwind under perf script. The
reason is that perf script does not properly configure
callchain_param.record_mode, which is needed by unwind code.

Stealing the code from report and leaving the place for more
initialization code in a hope we could merge it with
report__setup_sample_type one day.

Reported-by: Milian Wolff <[email protected]>
Signed-off-by: Jiri Olsa <[email protected]>
Tested-by: Milian Wolff <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
---
tools/perf/builtin-script.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 7b376d2..105332e 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1561,6 +1561,22 @@ static int have_cmd(int argc, const char **argv)
return 0;
}

+static void script__setup_sample_type(struct perf_script *script)
+{
+ struct perf_session *session = script->session;
+ u64 sample_type = perf_evlist__combined_sample_type(session->evlist);
+
+ if (symbol_conf.use_callchain || symbol_conf.cumulate_callchain) {
+ if ((sample_type & PERF_SAMPLE_REGS_USER) &&
+ (sample_type & PERF_SAMPLE_STACK_USER))
+ callchain_param.record_mode = CALLCHAIN_DWARF;
+ else if (sample_type & PERF_SAMPLE_BRANCH_STACK)
+ callchain_param.record_mode = CALLCHAIN_LBR;
+ else
+ callchain_param.record_mode = CALLCHAIN_FP;
+ }
+}
+
int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
{
bool show_full_info = false;
@@ -1849,6 +1865,7 @@ int cmd_script(int argc, const char **argv, const char *prefix __maybe_unused)
goto out_delete;

script.session = session;
+ script__setup_sample_type(&script);

session->itrace_synth_opts = &itrace_synth_opts;