[PATCH] perf tools: Synthesize anon MMAP records on the heap

[PATCH] perf tools: Synthesize anon MMAP records on the heap

[Gaurav Jain]

Anon records usually do not have the 'execname' entry. However if they are on
the heap, the execname shows up as '[heap]'. The fix considers any executable
entries in the map that do not have a name or are on the heap as anon records
and sets the name to '//anon'.

This fixes JIT profiling for records on the heap.

Signed-off-by: Gaurav Jain <gjain@fb.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Arun Sharma <asharma@fb.com>
---
 tools/perf/util/event.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index bb788c1..ae9c55b 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -224,10 +224,9 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
 				continue;
 
 			event->header.misc |= PERF_RECORD_MISC_MMAP_DATA;
-		}
-
-		if (!strcmp(execname, ""))
+		} if (!strcmp(execname, "") || !strcmp(execname, "[heap]")) {
 			strcpy(execname, anonstr);
+		}
 
 		size = strlen(execname) + 1;
 		memcpy(event->mmap.filename, execname, size);
-- 
1.8.1

Re: [PATCH] perf tools: Synthesize anon MMAP records on the heap

[Namhyung Kim]

Hi Gaurav,

On Sat, 11 Jan 2014 20:32:14 -0800, Gaurav Jain wrote:
> Anon records usually do not have the 'execname' entry. However if they are on
> the heap, the execname shows up as '[heap]'. The fix considers any executable
> entries in the map that do not have a name or are on the heap as anon records
> and sets the name to '//anon'.
>
> This fixes JIT profiling for records on the heap.

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung

Re: [PATCH] perf tools: Synthesize anon MMAP records on the heap

[Don Zickus]

On Sat, Jan 11, 2014 at 08:32:14PM -0800, Gaurav Jain wrote:
> Anon records usually do not have the 'execname' entry. However if they are on
> the heap, the execname shows up as '[heap]'. The fix considers any executable
> entries in the map that do not have a name or are on the heap as anon records
> and sets the name to '//anon'.
> 
> This fixes JIT profiling for records on the heap.

I guess I don't understand the need for this fix.  It seems breaking out
//anon vs. [heap] would be useful.  Your patch is saying otherwise.  Can
give a description of the problem you are trying to solve?

Also style issue below..

> 
> Signed-off-by: Gaurav Jain <gjain@fb.com>
> Cc: Ingo Molnar <mingo@kernel.org>
> Cc: Jiri Olsa <jolsa@redhat.com>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Don Zickus <dzickus@redhat.com>
> Cc: Arun Sharma <asharma@fb.com>
> ---
>  tools/perf/util/event.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
> index bb788c1..ae9c55b 100644
> --- a/tools/perf/util/event.c
> +++ b/tools/perf/util/event.c
> @@ -224,10 +224,9 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
>  				continue;
>  
>  			event->header.misc |= PERF_RECORD_MISC_MMAP_DATA;
> -		}
> -
> -		if (!strcmp(execname, ""))
> +		} if (!strcmp(execname, "") || !strcmp(execname, "[heap]")) {

The '} if' part should seperate the 'if' on to its own line (unless you
meant an 'else' in there).

Cheers,
Don

Re: [PATCH] perf tools: Synthesize anon MMAP records on the heap

[Gaurav Jain]

On 1/13/14, 11:54 AM, "Don Zickus" <dzickus@redhat.com> wrote:

>On Sat, Jan 11, 2014 at 08:32:14PM -0800, Gaurav Jain wrote:
>> Anon records usually do not have the 'execname' entry. However if they
>>are on
>> the heap, the execname shows up as '[heap]'. The fix considers any
>>executable
>> entries in the map that do not have a name or are on the heap as anon
>>records
>> and sets the name to '//anon'.
>> 
>> This fixes JIT profiling for records on the heap.
>
>I guess I don't understand the need for this fix.  It seems breaking out
>//anon vs. [heap] would be useful.  Your patch is saying otherwise.  Can
>give a description of the problem you are trying to solve?

Thank you for looking at the patch.

We generate a perf map file which includes certain JIT¹ed functions that
show up as [heap] entries. As a result, I included the executable heap
entries as anon pages so that it would be handled in
util/map.c:map__new(). The alternative would be to handle heap entries in
map__new() directly, however I wasn¹t sure if this would break something
as it seems that heap and stack entries are expected to fail all
map__find_* functions. Thus I considered executable heap entries as
//anon, but perhaps there is a better way.

>Also style issue below..
>
>> 
>> Signed-off-by: Gaurav Jain <gjain@fb.com>
>> Cc: Ingo Molnar <mingo@kernel.org>
>> Cc: Jiri Olsa <jolsa@redhat.com>
>> Cc: Paul Mackerras <paulus@samba.org>
>> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
>> Cc: Don Zickus <dzickus@redhat.com>
>> Cc: Arun Sharma <asharma@fb.com>
>> ---
>>  tools/perf/util/event.c | 5 ++---
>>  1 file changed, 2 insertions(+), 3 deletions(-)
>> 
>> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
>> index bb788c1..ae9c55b 100644
>> --- a/tools/perf/util/event.c
>> +++ b/tools/perf/util/event.c
>> @@ -224,10 +224,9 @@ static int
>>perf_event__synthesize_mmap_events(struct perf_tool *tool,
>>  				continue;
>>  
>>  			event->header.misc |= PERF_RECORD_MISC_MMAP_DATA;
>> -		}
>> -
>> -		if (!strcmp(execname, ""))
>> +		} if (!strcmp(execname, "") || !strcmp(execname, "[heap]")) {
>
>The '} if' part should seperate the 'if' on to its own line (unless you
>meant an 'else' in there).

Bah yes, I intended 'else if'. I apologize for that. Does the fact that I
filtered anon entries to only those marked as executable break the
existing behavior?

Thanks,

Gaurav

Re: [PATCH] perf tools: Synthesize anon MMAP records on the heap

[Namhyung Kim]

Hi Gaurav,

I'd like to take my ack back - it seems I missed some points.


On Tue, 14 Jan 2014 20:48:23 +0000, Gaurav Jain wrote:
> On 1/13/14, 11:54 AM, "Don Zickus" <dzickus@redhat.com> wrote:
>
>>On Sat, Jan 11, 2014 at 08:32:14PM -0800, Gaurav Jain wrote:
>>> Anon records usually do not have the 'execname' entry. However if they
>>>are on
>>> the heap, the execname shows up as '[heap]'. The fix considers any
>>>executable
>>> entries in the map that do not have a name or are on the heap as anon
>>>records
>>> and sets the name to '//anon'.
>>> 
>>> This fixes JIT profiling for records on the heap.
>>
>>I guess I don't understand the need for this fix.  It seems breaking out
>>//anon vs. [heap] would be useful.  Your patch is saying otherwise.  Can
>>give a description of the problem you are trying to solve?
>
> Thank you for looking at the patch.
>
> We generate a perf map file which includes certain JIT¹ed functions that
> show up as [heap] entries. As a result, I included the executable heap
> entries as anon pages so that it would be handled in
> util/map.c:map__new(). The alternative would be to handle heap entries in
> map__new() directly, however I wasn¹t sure if this would break something
> as it seems that heap and stack entries are expected to fail all
> map__find_* functions. Thus I considered executable heap entries as
> //anon, but perhaps there is a better way.

Hmm.. so the point is that an executable heap mapping should have
/tmp/perf-XXX.map as a file name, right?  If so, does something like
below work well for you?

Thanks,
Namhyung


diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 9b9bd719aa19..d52387fe83f1 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -69,7 +69,7 @@ struct map *map__new(struct list_head *dsos__list, u64 start, u64 len,
 		map->ino = ino;
 		map->ino_generation = ino_gen;
 
-		if (anon) {
+		if (anon || (no_dso && type == MAP__FUNCTION)) {
 			snprintf(newfilename, sizeof(newfilename), "/tmp/perf-%d.map", pid);
 			filename = newfilename;
 		}
@@ -93,7 +93,7 @@ struct map *map__new(struct list_head *dsos__list, u64 start, u64 len,
 			 * functions still return NULL, and we avoid the
 			 * unnecessary map__load warning.
 			 */
-			if (no_dso)
+			if (no_dso && type != MAP__FUNCTION)
 				dso__set_loaded(dso, map->type);
 		}
 	}

Re: [PATCH] perf tools: Synthesize anon MMAP records on the heap

[Gaurav Jain]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="euc-kr", Size: 2851 bytes --]

Hi Namhyung,


On 1/15/14, 12:46 AM, "Namhyung Kim" <namhyung@kernel.org> wrote:

>I'd like to take my ack back - it seems I missed some points.

No worries, looks like the patch wasn¡¯t well thought out.

>On Tue, 14 Jan 2014 20:48:23 +0000, Gaurav Jain wrote:
>> On 1/13/14, 11:54 AM, "Don Zickus" <dzickus@redhat.com> wrote:
>>
>>>On Sat, Jan 11, 2014 at 08:32:14PM -0800, Gaurav Jain wrote:
>>>> Anon records usually do not have the 'execname' entry. However if they
>>>>are on
>>>> the heap, the execname shows up as '[heap]'. The fix considers any
>>>>executable
>>>> entries in the map that do not have a name or are on the heap as anon
>>>>records
>>>> and sets the name to '//anon'.
>>>> 
>>>> This fixes JIT profiling for records on the heap.
>>>
>>>I guess I don't understand the need for this fix.  It seems breaking out
>>>//anon vs. [heap] would be useful.  Your patch is saying otherwise.  Can
>>>give a description of the problem you are trying to solve?
>>
>> Thank you for looking at the patch.
>>
>> We generate a perf map file which includes certain JIT©öed functions that
>> show up as [heap] entries. As a result, I included the executable heap
>> entries as anon pages so that it would be handled in
>> util/map.c:map__new(). The alternative would be to handle heap entries
>>in
>> map__new() directly, however I wasn©öt sure if this would break something
>> as it seems that heap and stack entries are expected to fail all
>> map__find_* functions. Thus I considered executable heap entries as
>> //anon, but perhaps there is a better way.
>
>Hmm.. so the point is that an executable heap mapping should have
>/tmp/perf-XXX.map as a file name, right?  If so, does something like
>below work well for you?

Just gave it a try and it fixed the issue perfectly! Thanks for the help.
This looks like a much better solution than treating the heap mapping as
an anon record.

Gaurav

>diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
>index 9b9bd719aa19..d52387fe83f1 100644
>--- a/tools/perf/util/map.c
>+++ b/tools/perf/util/map.c
>@@ -69,7 +69,7 @@ struct map *map__new(struct list_head *dsos__list, u64
>start, u64 len,
> 		map->ino = ino;
> 		map->ino_generation = ino_gen;
> 
>-		if (anon) {
>+		if (anon || (no_dso && type == MAP__FUNCTION)) {
> 			snprintf(newfilename, sizeof(newfilename), "/tmp/perf-%d.map", pid);
> 			filename = newfilename;
> 		}
>@@ -93,7 +93,7 @@ struct map *map__new(struct list_head *dsos__list, u64
>start, u64 len,
> 			 * functions still return NULL, and we avoid the
> 			 * unnecessary map__load warning.
> 			 */
>-			if (no_dso)
>+			if (no_dso && type != MAP__FUNCTION)
> 				dso__set_loaded(dso, map->type);
> 		}
> 	}

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Re: [PATCH] perf tools: Synthesize anon MMAP records on the heap

[Namhyung Kim]

Hi Gaurav,

On Wed, 15 Jan 2014 06:44:39 +0000, Gaurav Jain wrote:
> Hi Namhyung,
>
>
> On 1/15/14, 12:46 AM, "Namhyung Kim" <namhyung@kernel.org> wrote:
>>Hmm.. so the point is that an executable heap mapping should have
>>/tmp/perf-XXX.map as a file name, right?  If so, does something like
>>below work well for you?
>
> Just gave it a try and it fixed the issue perfectly! Thanks for the help.
> This looks like a much better solution than treating the heap mapping as
> an anon record.

Thanks for testing!  It's good to hear it solved your problem. :)

>
> Gaurav
>
>>diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
>>index 9b9bd719aa19..d52387fe83f1 100644
>>--- a/tools/perf/util/map.c
>>+++ b/tools/perf/util/map.c
>>@@ -69,7 +69,7 @@ struct map *map__new(struct list_head *dsos__list, u64
>>start, u64 len,
>> 		map->ino = ino;
>> 		map->ino_generation = ino_gen;
>> 
>>-		if (anon) {
>>+		if (anon || (no_dso && type == MAP__FUNCTION)) {

Hmm.. I think it should check type of anon mapping too (assuming JIT
interface only provides function symbols, no?):

		if ((anon || no_dso) && type == MAP__FUNCTION)) {


>> 			snprintf(newfilename, sizeof(newfilename), "/tmp/perf-%d.map", pid);
>> 			filename = newfilename;
>> 		}
>>@@ -93,7 +93,7 @@ struct map *map__new(struct list_head *dsos__list, u64
>>start, u64 len,
>> 			 * functions still return NULL, and we avoid the
>> 			 * unnecessary map__load warning.
>> 			 */
>>-			if (no_dso)
>>+			if (no_dso && type != MAP__FUNCTION)

And it should be simply:

			if (type != MAP__FUNCTION)


>> 				dso__set_loaded(dso, map->type);
>> 		}
>> 	}

I'll update this and send a formal patch soon.  Could you please test it with
the new patch then?

Thanks,
Namhyung

Re: [PATCH] perf tools: Synthesize anon MMAP records on the heap

[Gaurav Jain]

Hi Namhyung,

> On Jan 15, 2014, at 8:01 PM, "Namhyung Kim" <namhyung@kernel.org> wrote:
> 
> Hi Gaurav,
> 
>> On Wed, 15 Jan 2014 06:44:39 +0000, Gaurav Jain wrote:
>> Hi Namhyung,
>> 
>> 
>>> On 1/15/14, 12:46 AM, "Namhyung Kim" <namhyung@kernel.org> wrote:
>>> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
>>> index 9b9bd719aa19..d52387fe83f1 100644
>>> --- a/tools/perf/util/map.c
>>> +++ b/tools/perf/util/map.c
>>> @@ -69,7 +69,7 @@ struct map *map__new(struct list_head *dsos__list, u64
>>> start, u64 len,
>>>        map->ino = ino;
>>>        map->ino_generation = ino_gen;
>>> 
>>> -        if (anon) {
>>> +        if (anon || (no_dso && type == MAP__FUNCTION)) {
> 
> Hmm.. I think it should check type of anon mapping too (assuming JIT
> interface only provides function symbols, no?):
> 
>        if ((anon || no_dso) && type == MAP__FUNCTION)) {

In that case, shouldn't we filter out all mappings that are not executable as I had intended to do in my original patch?

>>>            snprintf(newfilename, sizeof(newfilename), "/tmp/perf-%d.map", pid);
>>>            filename = newfilename;
>>>        }
>>> @@ -93,7 +93,7 @@ struct map *map__new(struct list_head *dsos__list, u64
>>> start, u64 len,
>>>             * functions still return NULL, and we avoid the
>>>             * unnecessary map__load warning.
>>>             */
>>> -            if (no_dso)
>>> +            if (no_dso && type != MAP__FUNCTION)
> 
> And it should be simply:
> 
>            if (type != MAP__FUNCTION)
> 
> 
>>>                dso__set_loaded(dso, map->type);
>>>        }
>>>    }
> 
> I'll update this and send a formal patch soon.  Could you please test it with
> the new patch then?

Sure I'll test the new patch, though please note my previous suggestion.

Gaurav

Re: [PATCH] perf tools: Synthesize anon MMAP records on the heap

[Don Zickus]

On Tue, Jan 14, 2014 at 08:48:23PM +0000, Gaurav Jain wrote:
> On 1/13/14, 11:54 AM, "Don Zickus" <dzickus@redhat.com> wrote:
> 
> >On Sat, Jan 11, 2014 at 08:32:14PM -0800, Gaurav Jain wrote:
> >> Anon records usually do not have the 'execname' entry. However if they
> >>are on
> >> the heap, the execname shows up as '[heap]'. The fix considers any
> >>executable
> >> entries in the map that do not have a name or are on the heap as anon
> >>records
> >> and sets the name to '//anon'.
> >> 
> >> This fixes JIT profiling for records on the heap.
> >
> >I guess I don't understand the need for this fix.  It seems breaking out
> >//anon vs. [heap] would be useful.  Your patch is saying otherwise.  Can
> >give a description of the problem you are trying to solve?
> 
> Thank you for looking at the patch.
> 
> We generate a perf map file which includes certain JIT¹ed functions that
> show up as [heap] entries. As a result, I included the executable heap
> entries as anon pages so that it would be handled in
> util/map.c:map__new(). The alternative would be to handle heap entries in
> map__new() directly, however I wasn¹t sure if this would break something
> as it seems that heap and stack entries are expected to fail all
> map__find_* functions. Thus I considered executable heap entries as
> //anon, but perhaps there is a better way.

Thanks for the improved problem description.   I see it led to a better
patch. :-)  That is why it is generally a good idea to describe the
problem you are trying to solve to see if others have a better solution.

Cheers,
Don

> 
> >Also style issue below..
> >
> >> 
> >> Signed-off-by: Gaurav Jain <gjain@fb.com>
> >> Cc: Ingo Molnar <mingo@kernel.org>
> >> Cc: Jiri Olsa <jolsa@redhat.com>
> >> Cc: Paul Mackerras <paulus@samba.org>
> >> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> >> Cc: Don Zickus <dzickus@redhat.com>
> >> Cc: Arun Sharma <asharma@fb.com>
> >> ---
> >>  tools/perf/util/event.c | 5 ++---
> >>  1 file changed, 2 insertions(+), 3 deletions(-)
> >> 
> >> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
> >> index bb788c1..ae9c55b 100644
> >> --- a/tools/perf/util/event.c
> >> +++ b/tools/perf/util/event.c
> >> @@ -224,10 +224,9 @@ static int
> >>perf_event__synthesize_mmap_events(struct perf_tool *tool,
> >>  				continue;
> >>  
> >>  			event->header.misc |= PERF_RECORD_MISC_MMAP_DATA;
> >> -		}
> >> -
> >> -		if (!strcmp(execname, ""))
> >> +		} if (!strcmp(execname, "") || !strcmp(execname, "[heap]")) {
> >
> >The '} if' part should seperate the 'if' on to its own line (unless you
> >meant an 'else' in there).
> 
> Bah yes, I intended 'else if'. I apologize for that. Does the fact that I
> filtered anon entries to only those marked as executable break the
> existing behavior?
> 
> Thanks,
> 
> Gaurav
> 

Re: [PATCH] perf tools: Synthesize anon MMAP records on the heap

[Namhyung Kim]

Hi Don,

On Wed, 15 Jan 2014 09:27:27 -0500, Don Zickus wrote:
> On Tue, Jan 14, 2014 at 08:48:23PM +0000, Gaurav Jain wrote:
>> On 1/13/14, 11:54 AM, "Don Zickus" <dzickus@redhat.com> wrote:
>> 
>> >On Sat, Jan 11, 2014 at 08:32:14PM -0800, Gaurav Jain wrote:
>> >> Anon records usually do not have the 'execname' entry. However if they
>> >>are on
>> >> the heap, the execname shows up as '[heap]'. The fix considers any
>> >>executable
>> >> entries in the map that do not have a name or are on the heap as anon
>> >>records
>> >> and sets the name to '//anon'.
>> >> 
>> >> This fixes JIT profiling for records on the heap.
>> >
>> >I guess I don't understand the need for this fix.  It seems breaking out
>> >//anon vs. [heap] would be useful.  Your patch is saying otherwise.  Can
>> >give a description of the problem you are trying to solve?
>> 
>> Thank you for looking at the patch.
>> 
>> We generate a perf map file which includes certain JIT¹ed functions that
>> show up as [heap] entries. As a result, I included the executable heap
>> entries as anon pages so that it would be handled in
>> util/map.c:map__new(). The alternative would be to handle heap entries in
>> map__new() directly, however I wasn¹t sure if this would break something
>> as it seems that heap and stack entries are expected to fail all
>> map__find_* functions. Thus I considered executable heap entries as
>> //anon, but perhaps there is a better way.
>
> Thanks for the improved problem description.   I see it led to a better
> patch. :-)  That is why it is generally a good idea to describe the
> problem you are trying to solve to see if others have a better solution.

Yes, thank you very much for pointing it out and helping to resolve this
issue!

Thanks,
Namhyung