[v5] perf: support specify vdso path in cmdline

[PATCH v5 4/8] perf: build-id: name debugging vdso as "debug"

Posted by Changbin Du 1 year, 5 months ago

As normal objects, we will add debugging vdso elf to build-id cache later.
Here we name the debugging one as "debug".

Signed-off-by: Changbin Du <changbin.du@huawei.com>
---
 tools/perf/util/build-id.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 83a1581e8cf1..15530af2bad9 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -259,8 +259,8 @@ static bool build_id_cache__valid_id(char *sbuild_id)
 static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso,
 					    bool is_debug)
 {
-	return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ?
-	    "debug" : "elf"));
+	return is_kallsyms ? "kallsyms" : (is_debug ? "debug" : (is_vdso ?
+		"vdso" : "elf"));
 }
 
 char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
-- 
2.34.1

Re: [PATCH v5 4/8] perf: build-id: name debugging vdso as "debug"

Posted by Adrian Hunter 1 year, 5 months ago

On 2/07/24 07:18, Changbin Du wrote:
> As normal objects, we will add debugging vdso elf to build-id cache later.
> Here we name the debugging one as "debug".
> 
> Signed-off-by: Changbin Du <changbin.du@huawei.com>
> ---
>  tools/perf/util/build-id.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> index 83a1581e8cf1..15530af2bad9 100644
> --- a/tools/perf/util/build-id.c
> +++ b/tools/perf/util/build-id.c
> @@ -259,8 +259,8 @@ static bool build_id_cache__valid_id(char *sbuild_id)
>  static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso,
>  					    bool is_debug)
>  {
> -	return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ?
> -	    "debug" : "elf"));
> +	return is_kallsyms ? "kallsyms" : (is_debug ? "debug" : (is_vdso ?
> +		"vdso" : "elf"));
>  }
>  
>  char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size,

To actually add "debug", this also needs:

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index 15530af2bad9..b5bd02a1ad0f 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -701,7 +701,7 @@ build_id_cache__add(const char *sbuild_id, const char *name, const char *realnam
 	 * file itself may not be very useful to users of our tools without a
 	 * symtab.
 	 */
-	if (!is_kallsyms && !is_vdso &&
+	if (!is_kallsyms &&
 	    strncmp(".ko", name + strlen(name) - 3, 3)) {
 		debugfile = build_id_cache__find_debug(sbuild_id, nsi, root_dir);
 		if (debugfile) {



With that perf will populated the "debug" entry in the build-id cache.
Currently, when adding to the build-id cache, perf only looks in
/usr/lib/debug/.build-id (refer build_id_cache__find_debug()), for
example:


$ sudo ln -s /lib/modules/6.9.2-local/build/arch/x86/entry/vdso/vdso64.so.dbg /usr/lib/debug/.build-id/cf/702469f4637840fd6ba1a8d8a628ff83253d04.debug
$ ls -l ~/.debug/\[vdso\]/cf702469f4637840fd6ba1a8d8a628ff83253d04/
total 8
-rw-r--r-- 1 ahunter ahunter    0 Jul 18 13:33 probes
-rw------- 1 ahunter ahunter 8192 Jul 18 13:33 vdso
$ perf record uname
Linux
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.010 MB perf.data (2 samples) ]
$ ls -l ~/.debug/\[vdso\]/cf702469f4637840fd6ba1a8d8a628ff83253d04/
total 40
-rwxrwxr-x 2 ahunter ahunter 32760 May 27 17:42 debug
-rw-r--r-- 1 ahunter ahunter     0 Jul 18 13:33 probes
-rw------- 1 ahunter ahunter  8192 Jul 18 13:33 vdso


Note, perf will anyway find the debug object in /usr/lib/debug/.build-id
so the benefit is if perf-archive is used to copy from the buildid-cache
to take to another machine.

Re: [PATCH v5 4/8] perf: build-id: name debugging vdso as "debug"

Posted by duchangbin 1 year, 4 months ago

On Thu, Jul 18, 2024 at 08:03:07PM +0300, Adrian Hunter wrote:
> On 2/07/24 07:18, Changbin Du wrote:
> > As normal objects, we will add debugging vdso elf to build-id cache later.
> > Here we name the debugging one as "debug".
> > 
> > Signed-off-by: Changbin Du <changbin.du@huawei.com>
> > ---
> >  tools/perf/util/build-id.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> > index 83a1581e8cf1..15530af2bad9 100644
> > --- a/tools/perf/util/build-id.c
> > +++ b/tools/perf/util/build-id.c
> > @@ -259,8 +259,8 @@ static bool build_id_cache__valid_id(char *sbuild_id)
> >  static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso,
> >  					    bool is_debug)
> >  {
> > -	return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ?
> > -	    "debug" : "elf"));
> > +	return is_kallsyms ? "kallsyms" : (is_debug ? "debug" : (is_vdso ?
> > +		"vdso" : "elf"));
> >  }
> >  
> >  char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
> 
> To actually add "debug", this also needs:
> 
> diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> index 15530af2bad9..b5bd02a1ad0f 100644
> --- a/tools/perf/util/build-id.c
> +++ b/tools/perf/util/build-id.c
> @@ -701,7 +701,7 @@ build_id_cache__add(const char *sbuild_id, const char *name, const char *realnam
>  	 * file itself may not be very useful to users of our tools without a
>  	 * symtab.
>  	 */
> -	if (!is_kallsyms && !is_vdso &&
> +	if (!is_kallsyms &&
>  	    strncmp(".ko", name + strlen(name) - 3, 3)) {
>  		debugfile = build_id_cache__find_debug(sbuild_id, nsi, root_dir);
>  		if (debugfile) {
> 
> 
> 
This is done by later patch named "perf: build-id: try to search debugging vdso
and add to cache". I split the changes into two patches.

> With that perf will populated the "debug" entry in the build-id cache.
> Currently, when adding to the build-id cache, perf only looks in
> /usr/lib/debug/.build-id (refer build_id_cache__find_debug()), for
> example:
> 
> 
> $ sudo ln -s /lib/modules/6.9.2-local/build/arch/x86/entry/vdso/vdso64.so.dbg /usr/lib/debug/.build-id/cf/702469f4637840fd6ba1a8d8a628ff83253d04.debug
> $ ls -l ~/.debug/\[vdso\]/cf702469f4637840fd6ba1a8d8a628ff83253d04/
> total 8
> -rw-r--r-- 1 ahunter ahunter    0 Jul 18 13:33 probes
> -rw------- 1 ahunter ahunter 8192 Jul 18 13:33 vdso
> $ perf record uname
> Linux
> [ perf record: Woken up 1 times to write data ]
> [ perf record: Captured and wrote 0.010 MB perf.data (2 samples) ]
> $ ls -l ~/.debug/\[vdso\]/cf702469f4637840fd6ba1a8d8a628ff83253d04/
> total 40
> -rwxrwxr-x 2 ahunter ahunter 32760 May 27 17:42 debug
> -rw-r--r-- 1 ahunter ahunter     0 Jul 18 13:33 probes
> -rw------- 1 ahunter ahunter  8192 Jul 18 13:33 vdso
> 
> 
> Note, perf will anyway find the debug object in /usr/lib/debug/.build-id
> so the benefit is if perf-archive is used to copy from the buildid-cache
> to take to another machine.
> 
> 

-- 
Cheers,
Changbin Du

Re: [PATCH v5 4/8] perf: build-id: name debugging vdso as "debug"

Posted by Adrian Hunter 1 year, 4 months ago

On 22/07/24 15:08, duchangbin wrote:
> On Thu, Jul 18, 2024 at 08:03:07PM +0300, Adrian Hunter wrote:
>> On 2/07/24 07:18, Changbin Du wrote:
>>> As normal objects, we will add debugging vdso elf to build-id cache later.
>>> Here we name the debugging one as "debug".
>>>
>>> Signed-off-by: Changbin Du <changbin.du@huawei.com>
>>> ---
>>>  tools/perf/util/build-id.c | 4 ++--
>>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
>>> index 83a1581e8cf1..15530af2bad9 100644
>>> --- a/tools/perf/util/build-id.c
>>> +++ b/tools/perf/util/build-id.c
>>> @@ -259,8 +259,8 @@ static bool build_id_cache__valid_id(char *sbuild_id)
>>>  static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso,
>>>  					    bool is_debug)
>>>  {
>>> -	return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ?
>>> -	    "debug" : "elf"));
>>> +	return is_kallsyms ? "kallsyms" : (is_debug ? "debug" : (is_vdso ?
>>> +		"vdso" : "elf"));
>>>  }
>>>  
>>>  char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
>>
>> To actually add "debug", this also needs:
>>
>> diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
>> index 15530af2bad9..b5bd02a1ad0f 100644
>> --- a/tools/perf/util/build-id.c
>> +++ b/tools/perf/util/build-id.c
>> @@ -701,7 +701,7 @@ build_id_cache__add(const char *sbuild_id, const char *name, const char *realnam
>>  	 * file itself may not be very useful to users of our tools without a
>>  	 * symtab.
>>  	 */
>> -	if (!is_kallsyms && !is_vdso &&
>> +	if (!is_kallsyms &&
>>  	    strncmp(".ko", name + strlen(name) - 3, 3)) {
>>  		debugfile = build_id_cache__find_debug(sbuild_id, nsi, root_dir);
>>  		if (debugfile) {
>>
>>
>>
> This is done by later patch named "perf: build-id: try to search debugging vdso
> and add to cache". I split the changes into two patches.

With the above, the split is more functionally logical:
	1. Add support for build-id cache vdso debug
	2. For vdso, extend build_id_cache__find_debug() to find
	local kernel build files

> 
>> With that perf will populated the "debug" entry in the build-id cache.
>> Currently, when adding to the build-id cache, perf only looks in
>> /usr/lib/debug/.build-id (refer build_id_cache__find_debug()), for
>> example:
>>
>>
>> $ sudo ln -s /lib/modules/6.9.2-local/build/arch/x86/entry/vdso/vdso64.so.dbg /usr/lib/debug/.build-id/cf/702469f4637840fd6ba1a8d8a628ff83253d04.debug
>> $ ls -l ~/.debug/\[vdso\]/cf702469f4637840fd6ba1a8d8a628ff83253d04/
>> total 8
>> -rw-r--r-- 1 ahunter ahunter    0 Jul 18 13:33 probes
>> -rw------- 1 ahunter ahunter 8192 Jul 18 13:33 vdso
>> $ perf record uname
>> Linux
>> [ perf record: Woken up 1 times to write data ]
>> [ perf record: Captured and wrote 0.010 MB perf.data (2 samples) ]
>> $ ls -l ~/.debug/\[vdso\]/cf702469f4637840fd6ba1a8d8a628ff83253d04/
>> total 40
>> -rwxrwxr-x 2 ahunter ahunter 32760 May 27 17:42 debug
>> -rw-r--r-- 1 ahunter ahunter     0 Jul 18 13:33 probes
>> -rw------- 1 ahunter ahunter  8192 Jul 18 13:33 vdso
>>
>>
>> Note, perf will anyway find the debug object in /usr/lib/debug/.build-id
>> so the benefit is if perf-archive is used to copy from the buildid-cache
>> to take to another machine.
>>
>>
>

Re: [PATCH v5 4/8] perf: build-id: name debugging vdso as "debug"

Posted by duchangbin 1 year, 4 months ago

On Mon, Jul 22, 2024 at 04:21:46PM +0300, Adrian Hunter wrote:
> On 22/07/24 15:08, duchangbin wrote:
> > On Thu, Jul 18, 2024 at 08:03:07PM +0300, Adrian Hunter wrote:
> >> On 2/07/24 07:18, Changbin Du wrote:
> >>> As normal objects, we will add debugging vdso elf to build-id cache later.
> >>> Here we name the debugging one as "debug".
> >>>
> >>> Signed-off-by: Changbin Du <changbin.du@huawei.com>
> >>> ---
> >>>  tools/perf/util/build-id.c | 4 ++--
> >>>  1 file changed, 2 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> >>> index 83a1581e8cf1..15530af2bad9 100644
> >>> --- a/tools/perf/util/build-id.c
> >>> +++ b/tools/perf/util/build-id.c
> >>> @@ -259,8 +259,8 @@ static bool build_id_cache__valid_id(char *sbuild_id)
> >>>  static const char *build_id_cache__basename(bool is_kallsyms, bool is_vdso,
> >>>  					    bool is_debug)
> >>>  {
> >>> -	return is_kallsyms ? "kallsyms" : (is_vdso ? "vdso" : (is_debug ?
> >>> -	    "debug" : "elf"));
> >>> +	return is_kallsyms ? "kallsyms" : (is_debug ? "debug" : (is_vdso ?
> >>> +		"vdso" : "elf"));
> >>>  }
> >>>  
> >>>  char *__dso__build_id_filename(const struct dso *dso, char *bf, size_t size,
> >>
> >> To actually add "debug", this also needs:
> >>
> >> diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> >> index 15530af2bad9..b5bd02a1ad0f 100644
> >> --- a/tools/perf/util/build-id.c
> >> +++ b/tools/perf/util/build-id.c
> >> @@ -701,7 +701,7 @@ build_id_cache__add(const char *sbuild_id, const char *name, const char *realnam
> >>  	 * file itself may not be very useful to users of our tools without a
> >>  	 * symtab.
> >>  	 */
> >> -	if (!is_kallsyms && !is_vdso &&
> >> +	if (!is_kallsyms &&
> >>  	    strncmp(".ko", name + strlen(name) - 3, 3)) {
> >>  		debugfile = build_id_cache__find_debug(sbuild_id, nsi, root_dir);
> >>  		if (debugfile) {
> >>
> >>
> >>
> > This is done by later patch named "perf: build-id: try to search debugging vdso
> > and add to cache". I split the changes into two patches.
> 
> With the above, the split is more functionally logical:
> 	1. Add support for build-id cache vdso debug
> 	2. For vdso, extend build_id_cache__find_debug() to find
> 	local kernel build files
>
Sounds good for me.

> > 
> >> With that perf will populated the "debug" entry in the build-id cache.
> >> Currently, when adding to the build-id cache, perf only looks in
> >> /usr/lib/debug/.build-id (refer build_id_cache__find_debug()), for
> >> example:
> >>
> >>
> >> $ sudo ln -s /lib/modules/6.9.2-local/build/arch/x86/entry/vdso/vdso64.so.dbg /usr/lib/debug/.build-id/cf/702469f4637840fd6ba1a8d8a628ff83253d04.debug
> >> $ ls -l ~/.debug/\[vdso\]/cf702469f4637840fd6ba1a8d8a628ff83253d04/
> >> total 8
> >> -rw-r--r-- 1 ahunter ahunter    0 Jul 18 13:33 probes
> >> -rw------- 1 ahunter ahunter 8192 Jul 18 13:33 vdso
> >> $ perf record uname
> >> Linux
> >> [ perf record: Woken up 1 times to write data ]
> >> [ perf record: Captured and wrote 0.010 MB perf.data (2 samples) ]
> >> $ ls -l ~/.debug/\[vdso\]/cf702469f4637840fd6ba1a8d8a628ff83253d04/
> >> total 40
> >> -rwxrwxr-x 2 ahunter ahunter 32760 May 27 17:42 debug
> >> -rw-r--r-- 1 ahunter ahunter     0 Jul 18 13:33 probes
> >> -rw------- 1 ahunter ahunter  8192 Jul 18 13:33 vdso
> >>
> >>
> >> Note, perf will anyway find the debug object in /usr/lib/debug/.build-id
> >> so the benefit is if perf-archive is used to copy from the buildid-cache
> >> to take to another machine.
> >>
> >>
> > 
> 
> 

-- 
Cheers,
Changbin Du