[PATCH] perf record: Add support to collect callchains from kernel or user space only.

[PATCH] perf record: Add support to collect callchains from kernel or user space only.

[ufo19890607]

From: yuzhoujian <yuzhoujian@didichuxing.com>

One can just record callchains in the kernel or user space with
this new options. We can use it together with "--all-kernel" options.
This two options is used just like print_stack(sys) or print_ustack(usr)
for systemtap.

Show below is the usage of this new option combined with "--all-kernel"
options.
	1. Configure all used events to run in kernel space and just
collect kernel callchains.
	$ perf record -a -g --all-kernel --kernel-callchains
	2. Configure all used events to run in kernel space and just
collect user callchains.
	$ perf record -a -g --all-kernel --user-callchains

Signed-off-by: yuzhoujian <yuzhoujian@didichuxing.com>
---
 tools/perf/Documentation/perf-record.txt | 6 ++++++
 tools/perf/builtin-record.c              | 4 ++++
 tools/perf/perf.h                        | 2 ++
 tools/perf/util/evsel.c                  | 4 ++++
 4 files changed, 16 insertions(+)

diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index de269430720a..b647eb3db0c6 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -490,6 +490,12 @@ Configure all used events to run in kernel space.
 --all-user::
 Configure all used events to run in user space.
 
+--kernel-callchains::
+Collect callchains from kernel space.
+
+--user-callchains::
+Collect callchains from user space.
+
 --timestamp-filename
 Append timestamp to output file name.
 
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index e2c3a585a61e..dca55997934e 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -2191,6 +2191,10 @@ static struct option __record_options[] = {
 	OPT_BOOLEAN_FLAG(0, "all-user", &record.opts.all_user,
 			 "Configure all used events to run in user space.",
 			 PARSE_OPT_EXCLUSIVE),
+	OPT_BOOLEAN(0, "kernel-callchains", &record.opts.kernel_callchains,
+		    "collect kernel callchains"),
+	OPT_BOOLEAN(0, "user-callchains", &record.opts.user_callchains,
+		    "collect user callchains"),
 	OPT_STRING(0, "clang-path", &llvm_param.clang_path, "clang path",
 		   "clang binary to use for compiling BPF scriptlets"),
 	OPT_STRING(0, "clang-opt", &llvm_param.clang_opt, "clang options",
diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index d59dee61b64d..711e009381ec 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -61,6 +61,8 @@ struct record_opts {
 	bool	     record_switch_events;
 	bool	     all_kernel;
 	bool	     all_user;
+	bool	     kernel_callchains;
+	bool	     user_callchains;
 	bool	     tail_synthesize;
 	bool	     overwrite;
 	bool	     ignore_missing_thread;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index a6f572a40deb..a606b2833e27 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -680,6 +680,10 @@ static void __perf_evsel__config_callchain(struct perf_evsel *evsel,
 
 	attr->sample_max_stack = param->max_stack;
 
+	if (opts->kernel_callchains)
+		attr->exclude_callchain_user = 1;
+	if (opts->user_callchains)
+		attr->exclude_callchain_kernel = 1;
 	if (param->record_mode == CALLCHAIN_LBR) {
 		if (!opts->branch_stack) {
 			if (attr->exclude_user) {
-- 
2.14.1

Re: [PATCH] perf record: Add support to collect callchains from kernel or user space only.

[禹舟键]

PING


ufo19890607 <ufo19890607@gmail.com> 于2019年5月30日周四 下午9:29写道：
>
> From: yuzhoujian <yuzhoujian@didichuxing.com>
>
> One can just record callchains in the kernel or user space with
> this new options. We can use it together with "--all-kernel" options.
> This two options is used just like print_stack(sys) or print_ustack(usr)
> for systemtap.
>
> Show below is the usage of this new option combined with "--all-kernel"
> options.
>         1. Configure all used events to run in kernel space and just
> collect kernel callchains.
>         $ perf record -a -g --all-kernel --kernel-callchains
>         2. Configure all used events to run in kernel space and just
> collect user callchains.
>         $ perf record -a -g --all-kernel --user-callchains
>
> Signed-off-by: yuzhoujian <yuzhoujian@didichuxing.com>
> ---
>  tools/perf/Documentation/perf-record.txt | 6 ++++++
>  tools/perf/builtin-record.c              | 4 ++++
>  tools/perf/perf.h                        | 2 ++
>  tools/perf/util/evsel.c                  | 4 ++++
>  4 files changed, 16 insertions(+)
>
> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> index de269430720a..b647eb3db0c6 100644
> --- a/tools/perf/Documentation/perf-record.txt
> +++ b/tools/perf/Documentation/perf-record.txt
> @@ -490,6 +490,12 @@ Configure all used events to run in kernel space.
>  --all-user::
>  Configure all used events to run in user space.
>
> +--kernel-callchains::
> +Collect callchains from kernel space.
> +
> +--user-callchains::
> +Collect callchains from user space.
> +
>  --timestamp-filename
>  Append timestamp to output file name.
>
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index e2c3a585a61e..dca55997934e 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -2191,6 +2191,10 @@ static struct option __record_options[] = {
>         OPT_BOOLEAN_FLAG(0, "all-user", &record.opts.all_user,
>                          "Configure all used events to run in user space.",
>                          PARSE_OPT_EXCLUSIVE),
> +       OPT_BOOLEAN(0, "kernel-callchains", &record.opts.kernel_callchains,
> +                   "collect kernel callchains"),
> +       OPT_BOOLEAN(0, "user-callchains", &record.opts.user_callchains,
> +                   "collect user callchains"),
>         OPT_STRING(0, "clang-path", &llvm_param.clang_path, "clang path",
>                    "clang binary to use for compiling BPF scriptlets"),
>         OPT_STRING(0, "clang-opt", &llvm_param.clang_opt, "clang options",
> diff --git a/tools/perf/perf.h b/tools/perf/perf.h
> index d59dee61b64d..711e009381ec 100644
> --- a/tools/perf/perf.h
> +++ b/tools/perf/perf.h
> @@ -61,6 +61,8 @@ struct record_opts {
>         bool         record_switch_events;
>         bool         all_kernel;
>         bool         all_user;
> +       bool         kernel_callchains;
> +       bool         user_callchains;
>         bool         tail_synthesize;
>         bool         overwrite;
>         bool         ignore_missing_thread;
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index a6f572a40deb..a606b2833e27 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -680,6 +680,10 @@ static void __perf_evsel__config_callchain(struct perf_evsel *evsel,
>
>         attr->sample_max_stack = param->max_stack;
>
> +       if (opts->kernel_callchains)
> +               attr->exclude_callchain_user = 1;
> +       if (opts->user_callchains)
> +               attr->exclude_callchain_kernel = 1;
>         if (param->record_mode == CALLCHAIN_LBR) {
>                 if (!opts->branch_stack) {
>                         if (attr->exclude_user) {
> --
> 2.14.1
>

Re: [PATCH] perf record: Add support to collect callchains from kernel or user space only.

[Jiri Olsa]

On Thu, May 30, 2019 at 02:29:22PM +0100, ufo19890607 wrote:
> From: yuzhoujian <yuzhoujian@didichuxing.com>
> 
> One can just record callchains in the kernel or user space with
> this new options. We can use it together with "--all-kernel" options.
> This two options is used just like print_stack(sys) or print_ustack(usr)
> for systemtap.
> 
> Show below is the usage of this new option combined with "--all-kernel"
> options.
> 	1. Configure all used events to run in kernel space and just
> collect kernel callchains.
> 	$ perf record -a -g --all-kernel --kernel-callchains
> 	2. Configure all used events to run in kernel space and just
> collect user callchains.
> 	$ perf record -a -g --all-kernel --user-callchains
> 
> Signed-off-by: yuzhoujian <yuzhoujian@didichuxing.com>

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka


> ---
>  tools/perf/Documentation/perf-record.txt | 6 ++++++
>  tools/perf/builtin-record.c              | 4 ++++
>  tools/perf/perf.h                        | 2 ++
>  tools/perf/util/evsel.c                  | 4 ++++
>  4 files changed, 16 insertions(+)
> 
> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> index de269430720a..b647eb3db0c6 100644
> --- a/tools/perf/Documentation/perf-record.txt
> +++ b/tools/perf/Documentation/perf-record.txt
> @@ -490,6 +490,12 @@ Configure all used events to run in kernel space.
>  --all-user::
>  Configure all used events to run in user space.
>  
> +--kernel-callchains::
> +Collect callchains from kernel space.
> +
> +--user-callchains::
> +Collect callchains from user space.
> +
>  --timestamp-filename
>  Append timestamp to output file name.
>  
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index e2c3a585a61e..dca55997934e 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -2191,6 +2191,10 @@ static struct option __record_options[] = {
>  	OPT_BOOLEAN_FLAG(0, "all-user", &record.opts.all_user,
>  			 "Configure all used events to run in user space.",
>  			 PARSE_OPT_EXCLUSIVE),
> +	OPT_BOOLEAN(0, "kernel-callchains", &record.opts.kernel_callchains,
> +		    "collect kernel callchains"),
> +	OPT_BOOLEAN(0, "user-callchains", &record.opts.user_callchains,
> +		    "collect user callchains"),
>  	OPT_STRING(0, "clang-path", &llvm_param.clang_path, "clang path",
>  		   "clang binary to use for compiling BPF scriptlets"),
>  	OPT_STRING(0, "clang-opt", &llvm_param.clang_opt, "clang options",
> diff --git a/tools/perf/perf.h b/tools/perf/perf.h
> index d59dee61b64d..711e009381ec 100644
> --- a/tools/perf/perf.h
> +++ b/tools/perf/perf.h
> @@ -61,6 +61,8 @@ struct record_opts {
>  	bool	     record_switch_events;
>  	bool	     all_kernel;
>  	bool	     all_user;
> +	bool	     kernel_callchains;
> +	bool	     user_callchains;
>  	bool	     tail_synthesize;
>  	bool	     overwrite;
>  	bool	     ignore_missing_thread;
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index a6f572a40deb..a606b2833e27 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -680,6 +680,10 @@ static void __perf_evsel__config_callchain(struct perf_evsel *evsel,
>  
>  	attr->sample_max_stack = param->max_stack;
>  
> +	if (opts->kernel_callchains)
> +		attr->exclude_callchain_user = 1;
> +	if (opts->user_callchains)
> +		attr->exclude_callchain_kernel = 1;
>  	if (param->record_mode == CALLCHAIN_LBR) {
>  		if (!opts->branch_stack) {
>  			if (attr->exclude_user) {
> -- 
> 2.14.1
> 

Re: [PATCH] perf record: Add support to collect callchains from kernel or user space only.

[Arnaldo Carvalho de Melo]

Em Thu, May 30, 2019 at 02:29:22PM +0100, ufo19890607 escreveu:
> From: yuzhoujian <yuzhoujian@didichuxing.com>
> 
> One can just record callchains in the kernel or user space with
> this new options. We can use it together with "--all-kernel" options.
> This two options is used just like print_stack(sys) or print_ustack(usr)
> for systemtap.
> 
> Show below is the usage of this new option combined with "--all-kernel"
> options.
> 	1. Configure all used events to run in kernel space and just
> collect kernel callchains.
> 	$ perf record -a -g --all-kernel --kernel-callchains
> 	2. Configure all used events to run in kernel space and just
> collect user callchains.
> 	$ perf record -a -g --all-kernel --user-callchains
> 
> Signed-off-by: yuzhoujian <yuzhoujian@didichuxing.com>
> ---
>  tools/perf/Documentation/perf-record.txt | 6 ++++++
>  tools/perf/builtin-record.c              | 4 ++++
>  tools/perf/perf.h                        | 2 ++
>  tools/perf/util/evsel.c                  | 4 ++++
>  4 files changed, 16 insertions(+)
> 
> diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> index de269430720a..b647eb3db0c6 100644
> --- a/tools/perf/Documentation/perf-record.txt
> +++ b/tools/perf/Documentation/perf-record.txt
> @@ -490,6 +490,12 @@ Configure all used events to run in kernel space.
>  --all-user::
>  Configure all used events to run in user space.
>  
> +--kernel-callchains::
> +Collect callchains from kernel space.

Ok, changing this to:

Collect callchains only from kernel space. I.e. this option sets
perf_event_attr.exclude_callchain_user to 1,
perf_event_attr.exclude_callchain_kernel to 0.

> +
> +--user-callchains::
> +Collect callchains from user space.

And this one to:
Collect callchains only from user space. I.e. this option sets

perf_event_attr.exclude_callchain_kernel to 1,
perf_event_attr.exclude_callchain_user to 0.


So that the user don't try using:

    pref record --user-callchains --kernel-callchains

expecting to get both user and kernel callchains and instead gets
nothing.

Ok?

- Arnaldo

> +
>  --timestamp-filename
>  Append timestamp to output file name.
>  
> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> index e2c3a585a61e..dca55997934e 100644
> --- a/tools/perf/builtin-record.c
> +++ b/tools/perf/builtin-record.c
> @@ -2191,6 +2191,10 @@ static struct option __record_options[] = {
>  	OPT_BOOLEAN_FLAG(0, "all-user", &record.opts.all_user,
>  			 "Configure all used events to run in user space.",
>  			 PARSE_OPT_EXCLUSIVE),
> +	OPT_BOOLEAN(0, "kernel-callchains", &record.opts.kernel_callchains,
> +		    "collect kernel callchains"),
> +	OPT_BOOLEAN(0, "user-callchains", &record.opts.user_callchains,
> +		    "collect user callchains"),
>  	OPT_STRING(0, "clang-path", &llvm_param.clang_path, "clang path",
>  		   "clang binary to use for compiling BPF scriptlets"),
>  	OPT_STRING(0, "clang-opt", &llvm_param.clang_opt, "clang options",
> diff --git a/tools/perf/perf.h b/tools/perf/perf.h
> index d59dee61b64d..711e009381ec 100644
> --- a/tools/perf/perf.h
> +++ b/tools/perf/perf.h
> @@ -61,6 +61,8 @@ struct record_opts {
>  	bool	     record_switch_events;
>  	bool	     all_kernel;
>  	bool	     all_user;
> +	bool	     kernel_callchains;
> +	bool	     user_callchains;
>  	bool	     tail_synthesize;
>  	bool	     overwrite;
>  	bool	     ignore_missing_thread;
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index a6f572a40deb..a606b2833e27 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -680,6 +680,10 @@ static void __perf_evsel__config_callchain(struct perf_evsel *evsel,
>  
>  	attr->sample_max_stack = param->max_stack;
>  
> +	if (opts->kernel_callchains)
> +		attr->exclude_callchain_user = 1;
> +	if (opts->user_callchains)
> +		attr->exclude_callchain_kernel = 1;
>  	if (param->record_mode == CALLCHAIN_LBR) {
>  		if (!opts->branch_stack) {
>  			if (attr->exclude_user) {
> -- 
> 2.14.1

-- 

- Arnaldo

Re: [PATCH] perf record: Add support to collect callchains from kernel or user space only.

[Arnaldo Carvalho de Melo]

Em Thu, Jun 06, 2019 at 11:26:44AM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Thu, May 30, 2019 at 02:29:22PM +0100, ufo19890607 escreveu:
> > From: yuzhoujian <yuzhoujian@didichuxing.com>
> > 
> > One can just record callchains in the kernel or user space with
> > this new options. We can use it together with "--all-kernel" options.
> > This two options is used just like print_stack(sys) or print_ustack(usr)
> > for systemtap.
> > 
> > Show below is the usage of this new option combined with "--all-kernel"
> > options.
> > 	1. Configure all used events to run in kernel space and just
> > collect kernel callchains.
> > 	$ perf record -a -g --all-kernel --kernel-callchains
> > 	2. Configure all used events to run in kernel space and just
> > collect user callchains.
> > 	$ perf record -a -g --all-kernel --user-callchains
> > 
> > Signed-off-by: yuzhoujian <yuzhoujian@didichuxing.com>
> > ---
> >  tools/perf/Documentation/perf-record.txt | 6 ++++++
> >  tools/perf/builtin-record.c              | 4 ++++
> >  tools/perf/perf.h                        | 2 ++
> >  tools/perf/util/evsel.c                  | 4 ++++
> >  4 files changed, 16 insertions(+)
> > 
> > diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> > index de269430720a..b647eb3db0c6 100644
> > --- a/tools/perf/Documentation/perf-record.txt
> > +++ b/tools/perf/Documentation/perf-record.txt
> > @@ -490,6 +490,12 @@ Configure all used events to run in kernel space.
> >  --all-user::
> >  Configure all used events to run in user space.
> >  
> > +--kernel-callchains::
> > +Collect callchains from kernel space.
> 
> Ok, changing this to:
> 
> Collect callchains only from kernel space. I.e. this option sets
> perf_event_attr.exclude_callchain_user to 1,
> perf_event_attr.exclude_callchain_kernel to 0.
> 
> > +
> > +--user-callchains::
> > +Collect callchains from user space.
> 
> And this one to:
> Collect callchains only from user space. I.e. this option sets
> 
> perf_event_attr.exclude_callchain_kernel to 1,
> perf_event_attr.exclude_callchain_user to 0.

Yeah, each of this options just sets the exclude bit for the undesired
callchains, not setting 0 for the desired, so I'm fixing up the doc I
suggested accordingly, my comment below remains valid tho:

> 
> So that the user don't try using:
> 
>     pref record --user-callchains --kernel-callchains
> 
> expecting to get both user and kernel callchains and instead gets
> nothing.
> 
> Ok?
> 
> - Arnaldo
> 
> > +
> >  --timestamp-filename
> >  Append timestamp to output file name.
> >  
> > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> > index e2c3a585a61e..dca55997934e 100644
> > --- a/tools/perf/builtin-record.c
> > +++ b/tools/perf/builtin-record.c
> > @@ -2191,6 +2191,10 @@ static struct option __record_options[] = {
> >  	OPT_BOOLEAN_FLAG(0, "all-user", &record.opts.all_user,
> >  			 "Configure all used events to run in user space.",
> >  			 PARSE_OPT_EXCLUSIVE),
> > +	OPT_BOOLEAN(0, "kernel-callchains", &record.opts.kernel_callchains,
> > +		    "collect kernel callchains"),
> > +	OPT_BOOLEAN(0, "user-callchains", &record.opts.user_callchains,
> > +		    "collect user callchains"),
> >  	OPT_STRING(0, "clang-path", &llvm_param.clang_path, "clang path",
> >  		   "clang binary to use for compiling BPF scriptlets"),
> >  	OPT_STRING(0, "clang-opt", &llvm_param.clang_opt, "clang options",
> > diff --git a/tools/perf/perf.h b/tools/perf/perf.h
> > index d59dee61b64d..711e009381ec 100644
> > --- a/tools/perf/perf.h
> > +++ b/tools/perf/perf.h
> > @@ -61,6 +61,8 @@ struct record_opts {
> >  	bool	     record_switch_events;
> >  	bool	     all_kernel;
> >  	bool	     all_user;
> > +	bool	     kernel_callchains;
> > +	bool	     user_callchains;
> >  	bool	     tail_synthesize;
> >  	bool	     overwrite;
> >  	bool	     ignore_missing_thread;
> > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> > index a6f572a40deb..a606b2833e27 100644
> > --- a/tools/perf/util/evsel.c
> > +++ b/tools/perf/util/evsel.c
> > @@ -680,6 +680,10 @@ static void __perf_evsel__config_callchain(struct perf_evsel *evsel,
> >  
> >  	attr->sample_max_stack = param->max_stack;
> >  
> > +	if (opts->kernel_callchains)
> > +		attr->exclude_callchain_user = 1;
> > +	if (opts->user_callchains)
> > +		attr->exclude_callchain_kernel = 1;
> >  	if (param->record_mode == CALLCHAIN_LBR) {
> >  		if (!opts->branch_stack) {
> >  			if (attr->exclude_user) {
> > -- 
> > 2.14.1
> 
> -- 
> 
> - Arnaldo

-- 

- Arnaldo

Re: [PATCH] perf record: Add support to collect callchains from kernel or user space only.

[Jiri Olsa]

On Thu, Jun 06, 2019 at 11:26:44AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Thu, May 30, 2019 at 02:29:22PM +0100, ufo19890607 escreveu:
> > From: yuzhoujian <yuzhoujian@didichuxing.com>
> > 
> > One can just record callchains in the kernel or user space with
> > this new options. We can use it together with "--all-kernel" options.
> > This two options is used just like print_stack(sys) or print_ustack(usr)
> > for systemtap.
> > 
> > Show below is the usage of this new option combined with "--all-kernel"
> > options.
> > 	1. Configure all used events to run in kernel space and just
> > collect kernel callchains.
> > 	$ perf record -a -g --all-kernel --kernel-callchains
> > 	2. Configure all used events to run in kernel space and just
> > collect user callchains.
> > 	$ perf record -a -g --all-kernel --user-callchains
> > 
> > Signed-off-by: yuzhoujian <yuzhoujian@didichuxing.com>
> > ---
> >  tools/perf/Documentation/perf-record.txt | 6 ++++++
> >  tools/perf/builtin-record.c              | 4 ++++
> >  tools/perf/perf.h                        | 2 ++
> >  tools/perf/util/evsel.c                  | 4 ++++
> >  4 files changed, 16 insertions(+)
> > 
> > diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
> > index de269430720a..b647eb3db0c6 100644
> > --- a/tools/perf/Documentation/perf-record.txt
> > +++ b/tools/perf/Documentation/perf-record.txt
> > @@ -490,6 +490,12 @@ Configure all used events to run in kernel space.
> >  --all-user::
> >  Configure all used events to run in user space.
> >  
> > +--kernel-callchains::
> > +Collect callchains from kernel space.
> 
> Ok, changing this to:
> 
> Collect callchains only from kernel space. I.e. this option sets
> perf_event_attr.exclude_callchain_user to 1,
> perf_event_attr.exclude_callchain_kernel to 0.
> 
> > +
> > +--user-callchains::
> > +Collect callchains from user space.
> 
> And this one to:
> Collect callchains only from user space. I.e. this option sets
> 
> perf_event_attr.exclude_callchain_kernel to 1,
> perf_event_attr.exclude_callchain_user to 0.
> 
> 
> So that the user don't try using:
> 
>     pref record --user-callchains --kernel-callchains
> 
> expecting to get both user and kernel callchains and instead gets
> nothing.

good catch.. we should add the logic to keep both (default)
in this case.. so do nothing ;-)

jirka

Re: [PATCH] perf record: Add support to collect callchains from kernel or user space only.

[Arnaldo Carvalho de Melo]

Em Thu, Jun 06, 2019 at 04:46:14PM +0200, Jiri Olsa escreveu:
> On Thu, Jun 06, 2019 at 11:26:44AM -0300, Arnaldo Carvalho de Melo wrote:
> > So that the user don't try using:

> >     pref record --user-callchains --kernel-callchains

> > expecting to get both user and kernel callchains and instead gets
> > nothing.
 
> good catch.. we should add the logic to keep both (default)
> in this case.. so do nothing ;-)

Yeah, not using both or using both should amount to the same behaviour.

Can be done with a patch on top of what I have in my tree now.

- Arnaldo

Re: [PATCH] perf record: Add support to collect callchains from kernel or user space only.

[禹舟键]

Hi Arnaldo,  Jirka

> perf_event_attr.exclude_callchain_kernel to 0

I don't think we should set 0 for the desired callchins,  because we
will set exclude_callchain_user to 1 if perf_evsel is function event.

void perf_evsel__config(struct perf_evsel *evsel, struct record_opts
*opts, struct callchain_param *callchain)
{
        ...
        if (perf_evsel__is_function_event(evsel))
                evsel->attr.exclude_callchain_user = 1;

        if (callchain && callchain->enabled && !evsel->no_aux_samples)
                perf_evsel__config_callchain(evsel, opts, callchain);
}

If we set exclude_callchain_user to 0 , it will catch user callchain
for function_event.  So, it will be best to just set the
exclude_callchain_xxx to 1.

> So that the user don't try using:

    > perf record --user-callchains --kernel-callchains

> expecting to get both user and kernel callchains and instead gets
> nothing.

I will add a note in the doc.


Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com> 于2019年6月7日周五 上午2:15写道：
>
> Em Thu, Jun 06, 2019 at 04:46:14PM +0200, Jiri Olsa escreveu:
> > On Thu, Jun 06, 2019 at 11:26:44AM -0300, Arnaldo Carvalho de Melo wrote:
> > > So that the user don't try using:
>
> > >     pref record --user-callchains --kernel-callchains
>
> > > expecting to get both user and kernel callchains and instead gets
> > > nothing.
>
> > good catch.. we should add the logic to keep both (default)
> > in this case.. so do nothing ;-)
>
> Yeah, not using both or using both should amount to the same behaviour.
>
> Can be done with a patch on top of what I have in my tree now.
>
> - Arnaldo