Re: [PATCH] Can OProfile support reproducible build?

[Michael Petlan <mpetlan@re...>]

Patch ping...? William, could you please commit it in?
Thank you.

On Thu, 31 Aug 2017, Michael Petlan wrote:
> Hi,
> 
> On Thu, 31 Aug 2017, William Cohen wrote:
> > Hi,
> > 
> > It would be fine to have a patch that strips out those things that prevent the build from being reproducible.  Both Fedora and Debian are have talked about moving towards reproducible builds:
> 
> ... something like the attached one?
> 
> Btw. I was trying to find where in doc the version string is
> documented and I found nothing...
> 
> > 
> > https://reproducible.alioth.debian.org/presentations/2017-01-27-devconf.cz-reproducible-builds+fedora.pdf
> > https://wiki.debian.org/ReproducibleBuilds/About
> > https://fedoraproject.org/wiki/Changes/RPM-4.14
> > 
> > -Will
> > 
> > > 
> > > On Thu, 31 Aug 2017, Zhongwenlin wrote:
> > >> Thank you.
> > >> I tried to replace the time stamps __DATE__ and __TIME__ macros by a fixed time string, and it works.
> > >> Can Oprofile add configurations or just remove the time stamps(if they are not necessary ) in future versions?
> > >>
> > >> -----邮件原件-----
> > >> 发件人: Michael Petlan [mailto:mpetlan@...] 
> > >> 发送时间: 2017年8月30日 22:35
> > >> 收件人: Zhongwenlin
> > >> 抄送: William Cohen; Gaokun (King); oprofile-list@...
> > >> 主题: RE: Can OProfile support reproducible build?
> > >>
> > >> Well, if just these three points are the whole show-stopper, we might make them conditional like
> > >>
> > >> #ifdef REPRODUCIBLE_BUILD
> > >>   cout << argv[0] << ": " << PACKAGE << " " << VERSION << endl; #else // the original stuff #endif
> > >>
> > >> ... or just remove the timestamps entirely...
> > >>
> > >> If you replace the __DATE__ and __TIME__ macros there by some dummy string, does it build reproducibly?
> > >>
> > >> Michael
> > >>
> > >> On Wed, 30 Aug 2017, Zhongwenlin wrote:
> > >>> Hi,
> > >>> I use the latest version 1.2.0. And I found that the code below would generate timestamps----just they cause the difference.
> > >>> How
> > >>>
> > >>>     libutil/op_version.c: 
> > >>>                     21: printf("%s: " PACKAGE " " VERSION " compiled on "
> > >>> 	                22：__DATE__ " " __TIME__ "\n", app_name);
> > >>>            
> > >>> 	pe_counting/ocount.cpp:
> > >>>                         659: case 'v':
> > >>> 			            660: cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
> > >>> 			            661:<< " " << __TIME__ << endl;
> > >>>
> > >>> 	pe_profiling/operf.cpp: 
> > >>>                       1344:case 'v':
> > >>> 			          1345:cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
> > >>> 			          1346:<< " " << __TIME__ << endl;
> > >>>
> > >>> How can I eliminate the timestamps?
> > >>>
> > >>>
> > >>> -----邮件原件-----
> > >>> 发件人: William Cohen [mailto:wcohen@...]
> > >>> 发送时间: 2017年8月29日 2:14
> > >>> 收件人: oprofile-list@...; Zhongwenlin
> > >>> 抄送: Gaokun (King)
> > >>> 主题: Can OProfile support reproducible build?
> > >>>
> > >>> From zhongwenlin@...:
> > >>>
> > >>>
> > >>> Hi,
> > >>>
> > >>> When I build Oprofile, I find the build results are different every time. It seems to be caused by some time stamps. How can I get rid of the time stamps?
> > >>>
> > >>> As we know, reproducible build is a good way to counter malicious attacks that generate malicious executables, by making it easy to recreate the executable to determine if the result is correct.  How can I eliminate the differences caused by the time stamps? Just remove some code? Or is there any configuration?
> > >>>
> > >>> Can Oprofile support reproducible build in later versions?
> > >>>
> > >>> Thank you.
> > >>>
> > >>>
> > >>>
> > >>> ---------------
> > >>>
> > >>>
> > >>> Hi,
> > >>>
> > >>> It would be helpful to describe in more detail which version of OProfile is being built, how OProfile is being built, and specific differences between the repeated builds.
> > >>>
> > >>> Debian does have some information on techniques on indentify reproducible build issues and ways to address them:
> > >>>
> > >>> https://wiki.debian.org/ReproducibleBuilds/Howto
> > >>>
> > >>> -Will
> > >>> ----------------------------------------------------------------------
> > >>> -------- Check out the vibrant tech community on one of the world's 
> > >>> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot 
> > >>> _______________________________________________
> > >>> oprofile-list mailing list
> > >>> oprofile-list@...
> > >>> https://lists.sourceforge.net/lists/listinfo/oprofile-list
> > >>>
> > 
> > 

Re: 答复: Can OProfile support reproducible build?

[Michael Petlan <mpetlan@re...>]

Hi,

On Thu, 31 Aug 2017, William Cohen wrote:
> Hi,
> 
> It would be fine to have a patch that strips out those things that prevent the build from being reproducible.  Both Fedora and Debian are have talked about moving towards reproducible builds:

... something like the attached one?

Btw. I was trying to find where in doc the version string is
documented and I found nothing...

> 
> https://reproducible.alioth.debian.org/presentations/2017-01-27-devconf.cz-reproducible-builds+fedora.pdf
> https://wiki.debian.org/ReproducibleBuilds/About
> https://fedoraproject.org/wiki/Changes/RPM-4.14
> 
> -Will
> 
> > 
> > On Thu, 31 Aug 2017, Zhongwenlin wrote:
> >> Thank you.
> >> I tried to replace the time stamps __DATE__ and __TIME__ macros by a fixed time string, and it works.
> >> Can Oprofile add configurations or just remove the time stamps(if they are not necessary ) in future versions?
> >>
> >> -----邮件原件-----
> >> 发件人: Michael Petlan [mailto:mpetlan@...] 
> >> 发送时间: 2017年8月30日 22:35
> >> 收件人: Zhongwenlin
> >> 抄送: William Cohen; Gaokun (King); oprofile-list@...
> >> 主题: RE: Can OProfile support reproducible build?
> >>
> >> Well, if just these three points are the whole show-stopper, we might make them conditional like
> >>
> >> #ifdef REPRODUCIBLE_BUILD
> >>   cout << argv[0] << ": " << PACKAGE << " " << VERSION << endl; #else // the original stuff #endif
> >>
> >> ... or just remove the timestamps entirely...
> >>
> >> If you replace the __DATE__ and __TIME__ macros there by some dummy string, does it build reproducibly?
> >>
> >> Michael
> >>
> >> On Wed, 30 Aug 2017, Zhongwenlin wrote:
> >>> Hi,
> >>> I use the latest version 1.2.0. And I found that the code below would generate timestamps----just they cause the difference.
> >>> How
> >>>
> >>>     libutil/op_version.c: 
> >>>                     21: printf("%s: " PACKAGE " " VERSION " compiled on "
> >>> 	                22：__DATE__ " " __TIME__ "\n", app_name);
> >>>            
> >>> 	pe_counting/ocount.cpp:
> >>>                         659: case 'v':
> >>> 			            660: cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
> >>> 			            661:<< " " << __TIME__ << endl;
> >>>
> >>> 	pe_profiling/operf.cpp: 
> >>>                       1344:case 'v':
> >>> 			          1345:cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
> >>> 			          1346:<< " " << __TIME__ << endl;
> >>>
> >>> How can I eliminate the timestamps?
> >>>
> >>>
> >>> -----邮件原件-----
> >>> 发件人: William Cohen [mailto:wcohen@...]
> >>> 发送时间: 2017年8月29日 2:14
> >>> 收件人: oprofile-list@...; Zhongwenlin
> >>> 抄送: Gaokun (King)
> >>> 主题: Can OProfile support reproducible build?
> >>>
> >>> From zhongwenlin@...:
> >>>
> >>>
> >>> Hi,
> >>>
> >>> When I build Oprofile, I find the build results are different every time. It seems to be caused by some time stamps. How can I get rid of the time stamps?
> >>>
> >>> As we know, reproducible build is a good way to counter malicious attacks that generate malicious executables, by making it easy to recreate the executable to determine if the result is correct.  How can I eliminate the differences caused by the time stamps? Just remove some code? Or is there any configuration?
> >>>
> >>> Can Oprofile support reproducible build in later versions?
> >>>
> >>> Thank you.
> >>>
> >>>
> >>>
> >>> ---------------
> >>>
> >>>
> >>> Hi,
> >>>
> >>> It would be helpful to describe in more detail which version of OProfile is being built, how OProfile is being built, and specific differences between the repeated builds.
> >>>
> >>> Debian does have some information on techniques on indentify reproducible build issues and ways to address them:
> >>>
> >>> https://wiki.debian.org/ReproducibleBuilds/Howto
> >>>
> >>> -Will
> >>> ----------------------------------------------------------------------
> >>> -------- Check out the vibrant tech community on one of the world's 
> >>> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot 
> >>> _______________________________________________
> >>> oprofile-list mailing list
> >>> oprofile-list@...
> >>> https://lists.sourceforge.net/lists/listinfo/oprofile-list
> >>>
> 
> 

Re: 答复: Can OProfile support reproducible build?

[William Cohen <wcohen@re...>]

On 08/31/2017 04:56 AM, Michael Petlan wrote:
> So in such case, I suggest either removing the strings entirely
> or making them conditional as I mentioned before. What would you
> prefer William?

Hi,

It would be fine to have a patch that strips out those things that prevent the build from being reproducible.  Both Fedora and Debian are have talked about moving towards reproducible builds:

https://reproducible.alioth.debian.org/presentations/2017-01-27-devconf.cz-reproducible-builds+fedora.pdf
https://wiki.debian.org/ReproducibleBuilds/About
https://fedoraproject.org/wiki/Changes/RPM-4.14

-Will

> 
> On Thu, 31 Aug 2017, Zhongwenlin wrote:
>> Thank you.
>> I tried to replace the time stamps __DATE__ and __TIME__ macros by a fixed time string, and it works.
>> Can Oprofile add configurations or just remove the time stamps(if they are not necessary ) in future versions?
>>
>> -----邮件原件-----
>> 发件人: Michael Petlan [mailto:mpetlan@...] 
>> 发送时间: 2017年8月30日 22:35
>> 收件人: Zhongwenlin
>> 抄送: William Cohen; Gaokun (King); oprofile-list@...
>> 主题: RE: Can OProfile support reproducible build?
>>
>> Well, if just these three points are the whole show-stopper, we might make them conditional like
>>
>> #ifdef REPRODUCIBLE_BUILD
>>   cout << argv[0] << ": " << PACKAGE << " " << VERSION << endl; #else // the original stuff #endif
>>
>> ... or just remove the timestamps entirely...
>>
>> If you replace the __DATE__ and __TIME__ macros there by some dummy string, does it build reproducibly?
>>
>> Michael
>>
>> On Wed, 30 Aug 2017, Zhongwenlin wrote:
>>> Hi,
>>> I use the latest version 1.2.0. And I found that the code below would generate timestamps----just they cause the difference.
>>> How
>>>
>>>     libutil/op_version.c: 
>>>                     21: printf("%s: " PACKAGE " " VERSION " compiled on "
>>> 	                22：__DATE__ " " __TIME__ "\n", app_name);
>>>            
>>> 	pe_counting/ocount.cpp:
>>>                         659: case 'v':
>>> 			            660: cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
>>> 			            661:<< " " << __TIME__ << endl;
>>>
>>> 	pe_profiling/operf.cpp: 
>>>                       1344:case 'v':
>>> 			          1345:cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
>>> 			          1346:<< " " << __TIME__ << endl;
>>>
>>> How can I eliminate the timestamps?
>>>
>>>
>>> -----邮件原件-----
>>> 发件人: William Cohen [mailto:wcohen@...]
>>> 发送时间: 2017年8月29日 2:14
>>> 收件人: oprofile-list@...; Zhongwenlin
>>> 抄送: Gaokun (King)
>>> 主题: Can OProfile support reproducible build?
>>>
>>> From zhongwenlin@...:
>>>
>>>
>>> Hi,
>>>
>>> When I build Oprofile, I find the build results are different every time. It seems to be caused by some time stamps. How can I get rid of the time stamps?
>>>
>>> As we know, reproducible build is a good way to counter malicious attacks that generate malicious executables, by making it easy to recreate the executable to determine if the result is correct.  How can I eliminate the differences caused by the time stamps? Just remove some code? Or is there any configuration?
>>>
>>> Can Oprofile support reproducible build in later versions?
>>>
>>> Thank you.
>>>
>>>
>>>
>>> ---------------
>>>
>>>
>>> Hi,
>>>
>>> It would be helpful to describe in more detail which version of OProfile is being built, how OProfile is being built, and specific differences between the repeated builds.
>>>
>>> Debian does have some information on techniques on indentify reproducible build issues and ways to address them:
>>>
>>> https://wiki.debian.org/ReproducibleBuilds/Howto
>>>
>>> -Will
>>> ----------------------------------------------------------------------
>>> -------- Check out the vibrant tech community on one of the world's 
>>> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot 
>>> _______________________________________________
>>> oprofile-list mailing list
>>> oprofile-list@...
>>> https://lists.sourceforge.net/lists/listinfo/oprofile-list
>>>

Re: 答复: Can OProfile support reproducible build?

[Michael Petlan <mpetlan@re...>]

So in such case, I suggest either removing the strings entirely
or making them conditional as I mentioned before. What would you
prefer William?

On Thu, 31 Aug 2017, Zhongwenlin wrote:
> Thank you.
> I tried to replace the time stamps __DATE__ and __TIME__ macros by a fixed time string, and it works.
> Can Oprofile add configurations or just remove the time stamps(if they are not necessary ) in future versions?
> 
> -----邮件原件-----
> 发件人: Michael Petlan [mailto:mpetlan@...] 
> 发送时间: 2017年8月30日 22:35
> 收件人: Zhongwenlin
> 抄送: William Cohen; Gaokun (King); oprofile-list@...
> 主题: RE: Can OProfile support reproducible build?
> 
> Well, if just these three points are the whole show-stopper, we might make them conditional like
> 
> #ifdef REPRODUCIBLE_BUILD
>   cout << argv[0] << ": " << PACKAGE << " " << VERSION << endl; #else // the original stuff #endif
> 
> ... or just remove the timestamps entirely...
> 
> If you replace the __DATE__ and __TIME__ macros there by some dummy string, does it build reproducibly?
> 
> Michael
> 
> On Wed, 30 Aug 2017, Zhongwenlin wrote:
> > Hi,
> > I use the latest version 1.2.0. And I found that the code below would generate timestamps----just they cause the difference.
> > How
> > 
> >     libutil/op_version.c: 
> >                     21: printf("%s: " PACKAGE " " VERSION " compiled on "
> > 	                22：__DATE__ " " __TIME__ "\n", app_name);
> >            
> > 	pe_counting/ocount.cpp:
> >                         659: case 'v':
> > 			            660: cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
> > 			            661:<< " " << __TIME__ << endl;
> > 
> > 	pe_profiling/operf.cpp: 
> >                       1344:case 'v':
> > 			          1345:cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
> > 			          1346:<< " " << __TIME__ << endl;
> > 
> > How can I eliminate the timestamps?
> > 
> > 
> > -----邮件原件-----
> > 发件人: William Cohen [mailto:wcohen@...]
> > 发送时间: 2017年8月29日 2:14
> > 收件人: oprofile-list@...; Zhongwenlin
> > 抄送: Gaokun (King)
> > 主题: Can OProfile support reproducible build?
> > 
> > From zhongwenlin@...:
> > 
> > 
> > Hi,
> > 
> > When I build Oprofile, I find the build results are different every time. It seems to be caused by some time stamps. How can I get rid of the time stamps?
> > 
> > As we know, reproducible build is a good way to counter malicious attacks that generate malicious executables, by making it easy to recreate the executable to determine if the result is correct.  How can I eliminate the differences caused by the time stamps? Just remove some code? Or is there any configuration?
> > 
> > Can Oprofile support reproducible build in later versions?
> > 
> > Thank you.
> > 
> > 
> > 
> > ---------------
> > 
> > 
> > Hi,
> > 
> > It would be helpful to describe in more detail which version of OProfile is being built, how OProfile is being built, and specific differences between the repeated builds.
> > 
> > Debian does have some information on techniques on indentify reproducible build issues and ways to address them:
> > 
> > https://wiki.debian.org/ReproducibleBuilds/Howto
> > 
> > -Will
> > ----------------------------------------------------------------------
> > -------- Check out the vibrant tech community on one of the world's 
> > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot 
> > _______________________________________________
> > oprofile-list mailing list
> > oprofile-list@...
> > https://lists.sourceforge.net/lists/listinfo/oprofile-list
> > 
> 

答复: Can OProfile support reproducible build?

[Zhongwenlin <zhongwenlin@hu...>]

Thank you.
I tried to replace the time stamps __DATE__ and __TIME__ macros by a fixed time string, and it works.
Can Oprofile add configurations or just remove the time stamps(if they are not necessary ) in future versions?

-----邮件原件-----
发件人: Michael Petlan [mailto:mpetlan@...] 
发送时间: 2017年8月30日 22:35
收件人: Zhongwenlin
抄送: William Cohen; Gaokun (King); oprofile-list@...
主题: RE: Can OProfile support reproducible build?

Well, if just these three points are the whole show-stopper, we might make them conditional like

#ifdef REPRODUCIBLE_BUILD
  cout << argv[0] << ": " << PACKAGE << " " << VERSION << endl; #else // the original stuff #endif

... or just remove the timestamps entirely...

If you replace the __DATE__ and __TIME__ macros there by some dummy string, does it build reproducibly?

Michael

On Wed, 30 Aug 2017, Zhongwenlin wrote:
> Hi,
> I use the latest version 1.2.0. And I found that the code below would generate timestamps----just they cause the difference.
> How
> 
>     libutil/op_version.c: 
>                     21: printf("%s: " PACKAGE " " VERSION " compiled on "
> 	                22：__DATE__ " " __TIME__ "\n", app_name);
>            
> 	pe_counting/ocount.cpp:
>                         659: case 'v':
> 			            660: cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
> 			            661:<< " " << __TIME__ << endl;
> 
> 	pe_profiling/operf.cpp: 
>                       1344:case 'v':
> 			          1345:cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
> 			          1346:<< " " << __TIME__ << endl;
> 
> How can I eliminate the timestamps?
> 
> 
> -----邮件原件-----
> 发件人: William Cohen [mailto:wcohen@...]
> 发送时间: 2017年8月29日 2:14
> 收件人: oprofile-list@...; Zhongwenlin
> 抄送: Gaokun (King)
> 主题: Can OProfile support reproducible build?
> 
> From zhongwenlin@...:
> 
> 
> Hi,
> 
> When I build Oprofile, I find the build results are different every time. It seems to be caused by some time stamps. How can I get rid of the time stamps?
> 
> As we know, reproducible build is a good way to counter malicious attacks that generate malicious executables, by making it easy to recreate the executable to determine if the result is correct.  How can I eliminate the differences caused by the time stamps? Just remove some code? Or is there any configuration?
> 
> Can Oprofile support reproducible build in later versions?
> 
> Thank you.
> 
> 
> 
> ---------------
> 
> 
> Hi,
> 
> It would be helpful to describe in more detail which version of OProfile is being built, how OProfile is being built, and specific differences between the repeated builds.
> 
> Debian does have some information on techniques on indentify reproducible build issues and ways to address them:
> 
> https://wiki.debian.org/ReproducibleBuilds/Howto
> 
> -Will
> ----------------------------------------------------------------------
> -------- Check out the vibrant tech community on one of the world's 
> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot 
> _______________________________________________
> oprofile-list mailing list
> oprofile-list@...
> https://lists.sourceforge.net/lists/listinfo/oprofile-list
> 

RE: Can OProfile support reproducible build?

[Michael Petlan <mpetlan@re...>]

Well, if just these three points are the whole show-stopper,
we might make them conditional like

#ifdef REPRODUCIBLE_BUILD
  cout << argv[0] << ": " << PACKAGE << " " << VERSION << endl;
#else
// the original stuff
#endif

... or just remove the timestamps entirely...

If you replace the __DATE__ and __TIME__ macros there by some
dummy string, does it build reproducibly?

Michael

On Wed, 30 Aug 2017, Zhongwenlin wrote:
> Hi,
> I use the latest version 1.2.0. And I found that the code below would generate timestamps----just they cause the difference.
> How
> 
>     libutil/op_version.c: 
>                     21: printf("%s: " PACKAGE " " VERSION " compiled on "
> 	                22：__DATE__ " " __TIME__ "\n", app_name);
>            
> 	pe_counting/ocount.cpp:
>                         659: case 'v':
> 			            660: cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
> 			            661:<< " " << __TIME__ << endl;
> 
> 	pe_profiling/operf.cpp: 
>                       1344:case 'v':
> 			          1345:cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
> 			          1346:<< " " << __TIME__ << endl;
> 
> How can I eliminate the timestamps?
> 
> 
> -----邮件原件-----
> 发件人: William Cohen [mailto:wcohen@...] 
> 发送时间: 2017年8月29日 2:14
> 收件人: oprofile-list@...; Zhongwenlin
> 抄送: Gaokun (King)
> 主题: Can OProfile support reproducible build?
> 
> From zhongwenlin@...:
> 
> 
> Hi,
> 
> When I build Oprofile, I find the build results are different every time. It seems to be caused by some time stamps. How can I get rid of the time stamps?
> 
> As we know, reproducible build is a good way to counter malicious attacks that generate malicious executables, by making it easy to recreate the executable to determine if the result is correct.  How can I eliminate the differences caused by the time stamps? Just remove some code? Or is there any configuration?
> 
> Can Oprofile support reproducible build in later versions?
> 
> Thank you.
> 
> 
> 
> ---------------
> 
> 
> Hi,
> 
> It would be helpful to describe in more detail which version of OProfile is being built, how OProfile is being built, and specific differences between the repeated builds.
> 
> Debian does have some information on techniques on indentify reproducible build issues and ways to address them:
> 
> https://wiki.debian.org/ReproducibleBuilds/Howto
> 
> -Will
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> _______________________________________________
> oprofile-list mailing list
> oprofile-list@...
> https://lists.sourceforge.net/lists/listinfo/oprofile-list
> 

RE: Can OProfile support reproducible build?

[Zhongwenlin <zhongwenlin@hu...>]

Hi,
I use the latest version 1.2.0. And I found that the code below would generate timestamps----just they cause the difference.
How

    libutil/op_version.c: 
                    21: printf("%s: " PACKAGE " " VERSION " compiled on "
	                22：__DATE__ " " __TIME__ "\n", app_name);
           
	pe_counting/ocount.cpp:
                        659: case 'v':
			            660: cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
			            661:<< " " << __TIME__ << endl;

	pe_profiling/operf.cpp: 
                      1344:case 'v':
			          1345:cout << argv[0] << ": " << PACKAGE << " " << VERSION << " compiled on " << __DATE__
			          1346:<< " " << __TIME__ << endl;

How can I eliminate the timestamps?


-----邮件原件-----
发件人: William Cohen [mailto:wcohen@...] 
发送时间: 2017年8月29日 2:14
收件人: oprofile-list@...; Zhongwenlin
抄送: Gaokun (King)
主题: Can OProfile support reproducible build?

From zhongwenlin@...:


Hi,

When I build Oprofile, I find the build results are different every time. It seems to be caused by some time stamps. How can I get rid of the time stamps?

As we know, reproducible build is a good way to counter malicious attacks that generate malicious executables, by making it easy to recreate the executable to determine if the result is correct.  How can I eliminate the differences caused by the time stamps? Just remove some code? Or is there any configuration?

Can Oprofile support reproducible build in later versions?

Thank you.



---------------


Hi,

It would be helpful to describe in more detail which version of OProfile is being built, how OProfile is being built, and specific differences between the repeated builds.

Debian does have some information on techniques on indentify reproducible build issues and ways to address them:

https://wiki.debian.org/ReproducibleBuilds/Howto

-Will

Can OProfile support reproducible build?

[William Cohen <wcohen@re...>]

>From zhongwenlin@...:


Hi,

When I build Oprofile, I find the build results are different every time. It seems to be caused by some time stamps. How can I get rid of the time stamps?

As we know, reproducible build is a good way to counter malicious attacks that generate malicious executables, by making it easy to recreate the executable to determine if the result is correct.  How can I eliminate the differences caused by the time stamps? Just remove some code? Or is there any configuration?

Can Oprofile support reproducible build in later versions?

Thank you.



---------------


Hi,

It would be helpful to describe in more detail which version of OProfile is being built, how OProfile is being built, and specific differences between the repeated builds.

Debian does have some information on techniques on indentify reproducible build issues and ways to address them:

https://wiki.debian.org/ReproducibleBuilds/Howto

-Will

Can OProfile support reproducible build?

[Zhongwenlin <zhongwenlin@hu...>]

Hi,

When I build Oprofile, I find the build results are different every time. It seems to be caused by some time stamps. How can I get rid of the time stamps?

As we know, reproducible build is a good way to counter malicious attacks that generate malicious executables, by making it easy to recreate the executable to determine if the result is correct.  How can I eliminate the differences caused by the time stamps? Just remove some code? Or is there any configuration?

Can Oprofile support reproducible build in later versions?

Thank you.

Re: [PATCH] opjitconv: add initial manpage

[William Cohen <wcohen@re...>]

On 07/27/2017 09:02 PM, Roberto Oliveira wrote:
> 
> 
> 
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> 
> 
> 
> _______________________________________________
> oprofile-list mailing list
> oprofile-list@...
> https://lists.sourceforge.net/lists/listinfo/oprofile-list
> 


This patch to add a basic man page for opjitconv looks fine and has been merged into the oprofile git repo. -Will Cohen

Re: [PATCH] Fix macro in operf man page

[William Cohen <wcohen@re...>]

On 07/27/2017 04:02 PM, Roberto Oliveira wrote:
> 
> 
> 
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> 
> 
> 
> _______________________________________________
> oprofile-list mailing list
> oprofile-list@...
> https://lists.sourceforge.net/lists/listinfo/oprofile-list
> 

The typo fix looked fine so the patch has been applied.  Thanks -Will Cohen

[PATCH] opjitconv: add initial manpage

[Roberto Oliveira <rdutra@li...>]

[PATCH] Fix macro in operf man page

[Roberto Oliveira <rdutra@li...>]

Re: [PATCH] Fix typos in op_netburst.c file

[William Cohen <wcohen@re...>]

On 07/24/2017 01:50 PM, Roberto Oliveira wrote:
> From 986d7342fc79c9830f47c8bf3ab85dce63d0dac4 Mon Sep 17 00:00:00 2001
> From: Roberto Oliveira <robertoguimaraes8@...>
> Date: Mon, 24 Jul 2017 13:29:41 -0400
> Subject: [PATCH] Fix typos in op_netburst.c file
> 
> Fix 'conjuction' and 'occurances' typos in op_netburst.c
> 
> Signed-off-by: Roberto Oliveira <robertoguimaraes8@...>
> ---
>  libop/op_netburst.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/libop/op_netburst.c b/libop/op_netburst.c
> index 04198a23..658d84d9 100644
> --- a/libop/op_netburst.c
> +++ b/libop/op_netburst.c
> @@ -376,7 +376,7 @@ netburst_entry_t op_netburst_events[] = {
>       .desc = "Number of entries (clipped at 15) in the IOQ that are "
>           "active. An allocated entry can be a sector (64 bytes) "
>           "or a chunk of 8 bytes. This event must be programmed in "
> -         "conjuction with IOQ_allocation. All 'TYPE_BIT*' event-masks "
> +         "conjunction with IOQ_allocation. All 'TYPE_BIT*' event-masks "
>           "together are treated as a single 5-bit value",
>       .event_select = 0x1A,
>       .escr_select = 0x6,
> @@ -1475,7 +1475,7 @@ netburst_entry_t op_netburst_events[] = {
> 
>      /* 44 */
>      {.name = "MACHINE_CLEAR",
> -     .desc = "Number of occurances when the entire "
> +     .desc = "Number of occurrences when the entire "
>           "pipeline of the machine is cleared",
>       .event_select = 0x2,
>       .escr_select = 0x5,
> @@ -1486,7 +1486,7 @@ netburst_entry_t op_netburst_events[] = {
>           .desc = "Counts for a portion of the many cycles while the "
>               "machine is cleared for any cause. Use edge-"
>               "triggering for this bit only to get a count of "
> -             "occurances versus a duration",
> +             "occurrences versus a duration",
>           .bit = 0,
>          },
>          {.name = "MOCLEAR",
> 
> 
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> 
> 
> 
> _______________________________________________
> oprofile-list mailing list
> oprofile-list@...
> https://lists.sourceforge.net/lists/listinfo/oprofile-list
> 

The patch looks reasonable and has been merged into the oprofile git repostory.  Thanks -Will Cohen

Re: [patch] power9, remove event entries with 0x00 values.

[William Cohen <wcohen@re...>]

On 07/25/2017 12:59 PM, Will Schmidt wrote:
>     
> A few of the events in the power9 list have event numbers of all zero, which
> aren't useful to us.  The events have valid values elsewhere in the tables, so
> squash the zero entries.
> 
> Due credit, this was noticed and reported to me by Michael Petlan (mpetlan@...).
> 
> Signed-off-by:  Will Schmidt <will_schmidt@...>
> 
> 
> diff --git a/events/ppc64/power9/events b/events/ppc64/power9/events
> index 7264515..2116c9b 100644
> --- a/events/ppc64/power9/events
> +++ b/events/ppc64/power9/events
> @@ -865,12 +865,10 @@ event:0x000001688C counters:0       um:zero minimum:10000  name:PM_RC_USAGE : Co
>  event:0x00000468A6 counters:3       um:zero minimum:10000  name:PM_RD_CLEARING_SC : Read clearing SC
>  event:0x00000460A6 counters:3       um:zero minimum:10000  name:PM_RD_FORMING_SC : Read forming SC
>  event:0x00000268A8 counters:1       um:zero minimum:10000  name:PM_RD_HIT_PF : RD machine hit L3 PF machine
> -event:0x0000000 counters:5       um:zero minimum:10000  name:PM_RUN_CYC : Run_cycles
>  event:0x00000200F4 counters:1       um:zero minimum:10000  name:PM_RUN_CYC : Run_cycles
>  event:0x000003006C counters:2       um:zero minimum:100000 name:PM_RUN_CYC_SMT2_MODE : Cycles in which this thread's run latch is set and the core is in SMT2 mode
>  event:0x000002006C counters:1       um:zero minimum:100000 name:PM_RUN_CYC_SMT4_MODE : Cycles in which this thread's run latch is set and the core is in SMT4 mode
>  event:0x000001006C counters:0       um:zero minimum:100000 name:PM_RUN_CYC_ST_MODE : Cycles run latch is set and core is in ST mode
> -event:0x0000000 counters:4       um:zero minimum:10000  name:PM_RUN_INST_CMPL : Run_Instructions
>  event:0x00000400FA counters:3       um:zero minimum:10000  name:PM_RUN_INST_CMPL : Run_Instructions
>  event:0x00000400F4 counters:3       um:zero minimum:10000  name:PM_RUN_PURR : Run_PURR
>  event:0x0000010008 counters:0       um:zero minimum:10000  name:PM_RUN_SPURR : Run SPURR
> 
> 
> 
> ------------------------------------------------------------------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> _______________________________________________
> oprofile-list mailing list
> oprofile-list@...
> https://lists.sourceforge.net/lists/listinfo/oprofile-list
> 

The patch looks reasonable and has been merged into the oprofile git repository.  Thanks -Will Cohen

[patch] power9, remove event entries with 0x00 values.

[Will Schmidt <will_schmidt@vn...>]

    
A few of the events in the power9 list have event numbers of all zero, which
aren't useful to us.  The events have valid values elsewhere in the tables, so
squash the zero entries.

Due credit, this was noticed and reported to me by Michael Petlan (mpetlan@...).

Signed-off-by:  Will Schmidt <will_schmidt@...>


diff --git a/events/ppc64/power9/events b/events/ppc64/power9/events
index 7264515..2116c9b 100644
--- a/events/ppc64/power9/events
+++ b/events/ppc64/power9/events
@@ -865,12 +865,10 @@ event:0x000001688C counters:0       um:zero minimum:10000  name:PM_RC_USAGE : Co
 event:0x00000468A6 counters:3       um:zero minimum:10000  name:PM_RD_CLEARING_SC : Read clearing SC
 event:0x00000460A6 counters:3       um:zero minimum:10000  name:PM_RD_FORMING_SC : Read forming SC
 event:0x00000268A8 counters:1       um:zero minimum:10000  name:PM_RD_HIT_PF : RD machine hit L3 PF machine
-event:0x0000000 counters:5       um:zero minimum:10000  name:PM_RUN_CYC : Run_cycles
 event:0x00000200F4 counters:1       um:zero minimum:10000  name:PM_RUN_CYC : Run_cycles
 event:0x000003006C counters:2       um:zero minimum:100000 name:PM_RUN_CYC_SMT2_MODE : Cycles in which this thread's run latch is set and the core is in SMT2 mode
 event:0x000002006C counters:1       um:zero minimum:100000 name:PM_RUN_CYC_SMT4_MODE : Cycles in which this thread's run latch is set and the core is in SMT4 mode
 event:0x000001006C counters:0       um:zero minimum:100000 name:PM_RUN_CYC_ST_MODE : Cycles run latch is set and core is in ST mode
-event:0x0000000 counters:4       um:zero minimum:10000  name:PM_RUN_INST_CMPL : Run_Instructions
 event:0x00000400FA counters:3       um:zero minimum:10000  name:PM_RUN_INST_CMPL : Run_Instructions
 event:0x00000400F4 counters:3       um:zero minimum:10000  name:PM_RUN_PURR : Run_PURR
 event:0x0000010008 counters:0       um:zero minimum:10000  name:PM_RUN_SPURR : Run SPURR

Announcement: OProfile 1.2.0

[William Cohen <wcohen@re...>]

We are pleased to announce the general availability of OProfile 1.2.0.
You can download this release at:
	http://oprofile.sourceforge.net/download/

-Will Cohen


OProfile is a powerful system-wide profiler for Linux.
Read more at http://oprofile.sf.net

OProfile 1.2.0 has been released.

New features
------------

- New/updated Processor Support
    * ARM Cortex A17
    * IBM Power 9
    * IBM Power 8NV and NVL variants
    * IBM z13
    * Intel Goldmont
    * Intel Kabylake
    * Intel Xeon Phi (Knights Landing)
    * Achitecture specific events for Applied Micro X-Gene

Bug fixes
---------

Filed bug reports:
-------------------------------------------------------------------------
|  BUG ID   |  Summary 
|-----------|------------------------------------------------------------
|  286      | Compilation error: left shift of negative value
|  288      | oprofile fails to build with --enable-pch and gcc-6.2 
-------------------------------------------------------------------------

Other bug fixes and improvements without a filed report (e.g., posted to the list):
---------------
   - Fixed compile warning and errors when using GCC 6 or GCC 7
   - Avoid using deprecated readdir_r function
   - Store samples in the archive and search the appropriate places
     for samples
   - Only start the application if the perf events setup was successful
   - Corrections in the code and i386 events so "make check" tests pass


Known problems and limitations
-------------------------

- When using operf to profile multiple events, the absolute number of
  events recorded may be substantially fewer than expected. This can
  be due to known bug in the Linux kernel's Performance Events
  Subsystem that was fixed sometime between Linux kernel version 3.1
  and 3.5.

- Monitoring processes that frequently create and destroy threads via
  the "--pid" option can be problematic.  The pipes used within operf
  and ocount may fill up can cause these programs to hang and require
  multiple cntl-C to exit rather than successfully collecting data on
  fast spawning processes and children.

[PATCH] Fix typos in op_netburst.c file

[Roberto Oliveira <rdutra@li...>]

 From 986d7342fc79c9830f47c8bf3ab85dce63d0dac4 Mon Sep 17 00:00:00 2001
From: Roberto Oliveira <robertoguimaraes8@...>
Date: Mon, 24 Jul 2017 13:29:41 -0400
Subject: [PATCH] Fix typos in op_netburst.c file

Fix 'conjuction' and 'occurances' typos in op_netburst.c

Signed-off-by: Roberto Oliveira <robertoguimaraes8@...>
---
  libop/op_netburst.c | 6 +++---
  1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/libop/op_netburst.c b/libop/op_netburst.c
index 04198a23..658d84d9 100644
--- a/libop/op_netburst.c
+++ b/libop/op_netburst.c
@@ -376,7 +376,7 @@ netburst_entry_t op_netburst_events[] = {
       .desc = "Number of entries (clipped at 15) in the IOQ that are "
           "active. An allocated entry can be a sector (64 bytes) "
           "or a chunk of 8 bytes. This event must be programmed in "
-         "conjuction with IOQ_allocation. All 'TYPE_BIT*' event-masks "
+         "conjunction with IOQ_allocation. All 'TYPE_BIT*' event-masks "
           "together are treated as a single 5-bit value",
       .event_select = 0x1A,
       .escr_select = 0x6,
@@ -1475,7 +1475,7 @@ netburst_entry_t op_netburst_events[] = {

      /* 44 */
      {.name = "MACHINE_CLEAR",
-     .desc = "Number of occurances when the entire "
+     .desc = "Number of occurrences when the entire "
           "pipeline of the machine is cleared",
       .event_select = 0x2,
       .escr_select = 0x5,
@@ -1486,7 +1486,7 @@ netburst_entry_t op_netburst_events[] = {
           .desc = "Counts for a portion of the many cycles while the "
               "machine is cleared for any cause. Use edge-"
               "triggering for this bit only to get a count of "
-             "occurances versus a duration",
+             "occurrences versus a duration",
           .bit = 0,
          },
          {.name = "MOCLEAR",
-- 
2.13.3

Re: Fwd: Potential deadlock in operf when using --pid

[大平怜 <rei.odaira@gm...>]

Thanks for reviewing the patches, Will,

I am trying to remember the code....  As far as I understand, the comm
pipes are used only for newly spawned processes.  I need to investigate
more to see if they can be removed.

It is less likely, but theoretically it is possible that the comm pipe gets
full first and as a result the sample output pipe gets full next.  In any
case, my patches should solve the issue.


Thanks,
Rei Odaira

2017-06-30 14:50 GMT-05:00 William Cohen <wcohen@...>:

> On 06/24/2016 08:06 PM, 大平怜 wrote:
> > I forgot to include oprofile-list.
> >
> >
> > Regards,
> > Rei Odaira
> >
> > ---------- Forwarded message ----------
> > From: *大平怜* <rei.odaira@... <mailto:rei.odaira@...>>
> > Date: 2016-06-24 19:04 GMT-05:00
> > Subject: Re: Potential deadlock in operf when using --pid
> > To: William Cohen <wcohen@... <mailto:wcohen@...>>
> >
> >
> > Hi,
> >
> > Now I come back to this problem.
> >
> > I am attaching two patches to solve it.  They apply to the latest master
> in the git repository.  Please apply oprofile_avoid_deadlock_1.patch
> first and then oprofile_avoid_deadlock_2.patch. The first patch is just
> for refactoring the code to make the second patch possible, and the second
> patch is for the actual problem solving.
> >
> > So, the problem is that the operf-record process is blocked on a write
> to the sample output pipe when the pipe is full, while the operf-read
> process, which is the consumer of the pipe, cannot read from the pipe
> because it is blocked on a read from the comm pipe, to which the
> operf-record process is supposed to write.  Please refer to the previous
> emails for the detailed problem description.
> >
> >             |<--sample output pipe--|
> > operf-read  |-------comm pipe------>|  operf-record
> >             |<------comm pipe-------|
> >
> > My solution is to make the sample output pipe non-blocking on the
> operf-record side.  When the sample output pipe is full, instead of waiting
> on it, the operf-record process polls both the sample output pipe and the
> (read-end of) comm pipe.  If there is a message in the comm pipe from the
> operf-read process, the operf-record process handles it and writes a
> response to the comm pipe, so that the operf-read process can finish being
> blocked on the read from the comm pipe and eventually can consume the
> sample output pipe.
> >
> > There are some other ways to solve this problem, so any comments are
> welcome.  With my patches, you can finish profiling
> oprofile_multithread_test by a single ctrl-c. They passed all the tests in
> oprofile-tests.
> >
> >
> > Regards,
> > Rei Odaira
> >
>
>
>
>
> Hi Da Rei,
>
> Sorry for missing the patches to address rapid thread
> creation/deletion deadlock issue.  I have been taking a look at them.
> As a sanity check I ran the testsuite before and after the patches and
> things look the same.
>
> Test results before the patches:
>
>                 === oprofile Summary ===
>
> # of expected passes            149
>
> kernel version: 4.11.5-200.fc25.x86_64
> userspace version: oprofile 1.2.0git compiled on Jun 29 2017 13:59:35
>
>
> Test results after the patches:
>
>                 === oprofile Summary ===
>
> # of expected passes            149
>
> kernel version: 4.11.5-200.fc25.x86_64
> userspace version: oprofile 1.2.0git compiled on Jun 29 2017 14:10:33
>
>
> The patches does appear to help with the issue demonstrated with the
> reporducer oprofile_mutithread_test with operations per thread of
> 1000000.  However, with smaller number of operations per thread
> settings (100000) operf has issue getting connected:
>
> $ operf --pid 7555
> !!!! No samples collected !!!
> The target program/command ended before profiling was started.
> operf record init failed
> usage: operf [ options ] [ --system-wide | --pid <pid> | [ command [ args
> ] ] ]
> Error running profiler
>
>
> Or if it is able to connect (the process was paused with cntl-z and
> then put back in the foreground after oprofile had attached):
>
> $ operf --pid 7555
> ...
> Unable to collect samples for forked process 17240. Process may have ended
> before recording could be started.
> Unable to collect samples for forked process 17241. Process may have ended
> before recording could be started.
> Unable to collect samples for forked process 17242. Process may have ended
> before recording could be started.
> Unable to collect samples for forked process 17243. Process may have ended
> before recording could be started.
> Failed to mmap kernel profile data.
> This issue may be caused by a non-root user running multiple operf
> sessions simultaneously. Try running as root or increasing the value of
> /proc/sys/kernel/perf_event_mlock_kb to resolve the problem.
>
> Unable to collect samples for forked process 17245. Process may have ended
> before recording could be started.
>
>
> Is is notable that perf has similar problems it is unable to attach to
> quickly spawning processes
>
> $ perf record --pid 7555
> Error:
> The sys_perf_event_open() syscall returned with 3 (No such process) for
> event (cycles).
> /bin/dmesg may provide additional information.
> No CONFIG_PERF_EVENTS=y kernel support configured?
> [wcohen@... oprofile]$ perf record --pid 7555
> ^C[ perf record: Woken up 81 times to write data ]
>
> However "perf record --pid 7555" is able to collect data without issue
> if the 7555 is paused when "perf record" starts up.  I have let the
> perf developers know about this issue.
>
>
> The portion of oprofile the patches affect is not easy to follow, so I
> am still trying to make sure I fully understand the issue and that the
> patches address the issue without introducing some other issue.
> Earlier email has the following diagram:
>
>
>             |<--sample output pipe--|
> operf-read  |-------comm pipe------>|  operf-record
>             |<------comm pipe-------|
>
>
> The data in the sample "sample output pipe" stream includes the
> PERF_RECORD_FORK events.  The operf-read processes the
> PERF_RECORD_FORK events in the stream and sends pid back up the comm
> pipe for operf-record add another thread.
>
> Is the comm pipe only being used to communicate the new processes to be
> monitored?
>
> Would it be possible to have operf-record just do that directly rather
> than having to make a round trip from operf-record to operf-read and
> back to operf-record?  Seems like there is a lot of overhead when
> starting to monitoring a new thread.
>
> The patches implement polling to avoid the opef-record getting hung
> and in turn causing operf-read getting stuck when sample output pipe
> gets full.  Is there any way that the comm pipe might similarly get
> full and cause a hang?
>
> -Will
>

Re: Operf and Opreport outputs

[Michael Petlan <mpetlan@re...>]

Hi Dhara,

On Thu, 6 Jul 2017, dhara buch wrote:
> Hello,
> I tried the perf-hello.c file and found the results as you explained. It is very helpful to me. Now, for
> PERF_COUNT_HW_BRANCH_MISSES, I am getting varying values every time unlike PERF_COUNT_HW_INSTRUCTIONS.  

Try to compare:

PERF_COUNT_HW_BRANCH_INSTRUCTIONS against PERF_COUNT_HW_BRANCH_MISSES.

The first one is how many branching instructions have been used, the second is
how many branch predictions were wrong. I am always getting almost the same
values of _BRANCH_INSTRUCTIONS, the values of _BRANCH_MISSES differ. That
makes sense, since from some constant number of branch instructions (these
are conditional jumps, loops, etc), some were mispredicted. The branch
prediction works pretty well, but it is not 100% successful. I am getting
around 6% of missed branches:

 	PERF_COUNT_HW_BRANCH_INSTRUCTIONS = 4541
 	PERF_COUNT_HW_BRANCH_MISSES = 272

but another run slightly differs in _BRANCH_MISSES while still having the
same number of branch instructions:

 	PERF_COUNT_HW_BRANCH_INSTRUCTIONS = 4541
 	PERF_COUNT_HW_BRANCH_MISSES = 248



It seems that the "more effective" factorial computation function not only
consumes slightly less instructions and cycles, but it also consumes
slightly less branch instructions and the branch prediction works slightly
better there:

My results look like this:

Ineffective method:
 	PERF_COUNT_HW_BRANCH_INSTRUCTIONS = 4541
 	PERF_COUNT_HW_BRANCH_MISSES = 258

More effective method:
 	PERF_COUNT_HW_BRANCH_INSTRUCTIONS = 4334
 	PERF_COUNT_HW_BRANCH_MISSES = 97

This is expectable and expected.

> 
> To get count for only defined process,

You are counting only the process and, also, in my example, you are counting
just the code between myperf_event_restart() and myperf_event_stop() functions.

The only dust you see in the measurements is that kernel might suspend your
process and schedule some other process in meanwhile, which may invalidate
the caches or spoil the branch guessing (I don't know how exactly this works)
--> so you cannot expect the metrics such as branch misses, cycles, etc. to
be 100% deterministic from your point of view.

> I am trying to set perf_event_attr structure variables sample_type
> as PERF_SAMPLE_BRANCH_STACK and branch_sample_type as PERF_SAMPLE_BRANCH_USER. By doing so, I am getting error no. 5 by
> perf_event_open. What may be the problem?

These variables are for something completely different. See the manpage for
"perf_event_open". The syscall returns error, because you misconfigured the
perf_event_attr structure to invalid values.

As I've already said: You don't need to tweak anything else, you already are
counting just the process you want.

> 
> Dhara Buch

Cheers,
Michael

> 
> On Mon, Jun 19, 2017 at 5:51 PM, Michael Petlan <mpetlan@...> wrote:
>       On Mon, 19 Jun 2017, dhara buch wrote:
>       > Hello,
>       > Thanks a lot for the detailed explanation. I could understand the working of operf and opreport.
>       > Unlike operf, ocount counts each occurrence of the monitored event. In such a case, why ocount also gives
>       varying values of CPU_CLK_UNHALTED even when the monitored code doesn't get
>       > changed. Is it because of background processes? If so, then can we get event count for only monitored
>       command?
>
>       Hi Dhara,
>
>       it is kind of because of the background processes, but not in the way that ocount
>       would count also their CPU consumption. If you don't use '-s' option, ocount will
>       count only what your command does.
>
>       However, it counts either kernelspace, userspace or both (default if you are root).
>       This can be configured by the event's flags:
>
>       Both:
>       -e CPU_CLK_UNHALTED:0:1:1
>
>       Only kernelspace (used by the command, i.e. syscalls, etc):
>       -e CPU_CLK_UNHALTED:0:1:0
>
>       Only userspace (i.e. syscalls are excluded):
>       -e CPU_CLK_UNHALTED:0:0:1
>
>       (the format is (ocount): event:umask:kernelspace:userspace,
>       for operf it is: event:umask:sample_rate:kernelspace:userspace)
>
>       The numbers are slightly different each run because the process does not live in
>       vacuum. It is usually dynamically linked, it calls libraries, kernel switches
>       contexts, etc. All these things cause the differences. Also, the CPU optimizes
>       the execution with floating success, depending on what else runs there with it.
>       If the process is interrupted many times, the CPU consumption will be higher.
>
>       I have a sample code which I linked dynamically and statically. While the dyn.
>       linked executable always takes around 670,260 cycles, the statically linked one
>       takes around 380,202 and seems to be more steady. Since it is very simple code,
>       you can see that the linker-related stuff took more than 40% of the CPU cycles).
>
>       Executing a binary is so complex problem that there is no surprise that those
>       measurements give different values every time.
>
>       ........
>
>       TIP:
>
>       You can use either papi library or the built-in kernel support for counting
>       just a particular part of code, e.g. a function. I have attached one example
>       which uses perfevents kernel background. I have two functions for factorial
>       counting, one is slightly less effective than the other. I count cycles and
>       instructions for both. When executing repeatedly, you can see, that the inst.
>       count is the same all the time (at least on my laptop), but the cycles count
>       differs even for just the stuff in the functions which are very simple.
>
>       cc -o perf-hello perf-hello.c myperf.c
>       ./perf-hello
>
>       Ineffective method:
>               PERF_COUNT_HW_CPU_CYCLES = 32192
>               PERF_COUNT_HW_INSTRUCTIONS = 20681
>
>       More effective method:
>               PERF_COUNT_HW_CPU_CYCLES = 15931
>               PERF_COUNT_HW_INSTRUCTIONS = 19103
>
>       ........
>
>       Cheers,
>       Michael
> 
>
>       >
>       > Thank you,
>       >
>       > On Fri, Jun 16, 2017 at 4:52 PM, Michael Petlan <mpetlan@...> wrote:
>       >       On Fri, 16 Jun 2017, dhara buch wrote:
>       >       > Hello,
>       >       >
>       >       > Many days ago you had helped me a lot in using Oprofile in Virtual Machine. That time, I also had a
>       query regarding
>       >       > getting information from 'opreport --symbols --debuginfo' command.
>       >
>       >       Hello,
>       >
>       >       yeah, I remember...
>       >
>       >       >
>       >       > Actually, I am profiling a file1.c file with the following commands...
>       >       >
>       >       > 1. gcc -g file1.c -o file1
>       >       >
>       >       > 2. operf ./file1 --events=CPU_CLK_UNHALTED
>       >       >
>       >       > 3. opreport --symbols --debuginfo
>       >       >
>       >       > the output contains various lines where one line look follows:
>       >       >
>       >       > samples  %        linenr info                 image name               symbol name
>       >       >
>       >       > 2       12.5000  rsaimp.c:16                 rsaimp                   MM
>       >       > 2        12.5000  rsaimp.c:34                 rsaimp                   main
>       >       >
>       >       > When I execute commands 2 and 3 multiple times, each time I gwt the output for symbole name MM
>       (which is UDF in the
>       >       > program) but I don't get output for main every time.
>       >       >
>       >       This is kind of random, see below.
>       >
>       >       > Additionally,'' the sample % also vary every time I file operf command. I do not understand the
>       working of operf that
>       >       > how it gives different outputs for the same program.
>       >       >
>       >
>       >       How _counting_ works:
>       >
>       >       Each time an event happens in CPU (in our case -- CPU_CLK_UNHALTED -- one
>       >       CPU tick), its counter is incremented by one. This way, you can get the
>       >       whole number of how many times the event happened:
>       >
>       >       $ ocount ls
>       >       Events were actively counted for 1863267 nanoseconds.
>       >       Event counts (actual) for /bin/ls:
>       >                 Event                    Count                    % time counted
>       >                 CPU_CLK_UNHALTED         2,672,309                100.00
>       >
>       >       This means that there were 2.672 million CPU ticks necessary to execute
>       >       `ls`.
>       >
>       >       The tool for counting is *ocount*.
>       >
>       >
>       >       How _profiling_ works:
>       >
>       >       For profiling, events are counted the same way as when counting, but only
>       >       once per N event occurrences a "sample" is taken. A sample is a piece of
>       >       information about where in the code it happened, what was the context and
>       >       potentially call-stack, etc. This sample is saved into the oprofile_data
>       >       dir structure. When you finish profiling, opreport generates some overview
>       >       from the samples recorded.
>       >
>       >       Of course, taking sample causes some overhead. Thus, you cannot take it
>       >       each time the event counter increments. For this purpose, there is "sample
>       >       rate" value which divides the event counter and takes a sample only once
>       >       per "sample rate" occurrences. Thus, it is pretty random, which event
>       >       occurrence is picked for a sample.
>       >
>       >       Of course, your main() consumes CPU ticks and the counter is incremented,
>       >       but sometimes, one of these incrementations produces sample, sometimes not,
>       >       thus the function is missing.
>       >
>       >       You have 2 samples on each of the line in the report. That is really a low
>       >       number, so it is very probable that sometimes the samples hit main() and
>       >       sometimes not.
>       >
>       >       $ operf ls
>       >       Profiling done.
>       >
>       >       $ opreport
>       >       Using /root/oprofile_data/samples/ for samples directory.
>       >       CPU: Core 2, speed 2267 MHz (estimated)
>       >       Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit mask of 0x00 (Unhalted
>       core cycles) count 100000
>       >       CPU_CLK_UNHALT...|
>       >         samples|      %|
>       >       ------------------
>       >        -->   37 100.000 ls
>       >              CPU_CLK_UNHALT...|
>       >                samples|      %|
>       >                        ------------------
>       >                     27 72.9730 kallsyms
>       >                      5 13.5135 libc-2.19.so
>       >                      2  5.4054 ld-2.19.so
>       >                      1  2.7027 ls
>       >                      1  2.7027 ext4
>       >                      1  2.7027 libattr.so.1.1.0
>       >
>       >       You see that out of (estimated) 2.5-3.5 mil of event occurrences (which is
>       >       the scale `ls` usually needs on my PC), I got only 37 samples.
>       >
>       >       The sample rate for each event are in `ophelp` as "min count".
>       >
>       >       Why did I get 37 samples? My default setting of default event is:
>       >
>       >       $ ophelp -d
>       >       CPU_CLK_UNHALTED:100000:0:1:1
>       >       -------------------^^
>       >
>       >       This means that there is 1 sample per 100000 event occurrences.
>       >
>       >       You can tweak this value a bit, but note that oprofile won't let you set
>       >       the value to be too low, due to the overhead reasons.
>       >
>       >       Let's try 10000 (sampling 10 times more often):
>       >
>       >       $ operf -e CPU_CLK_UNHALTED:10000 ls
>       >       WARNING: Lost samples detected! See /root/oprofile_data/samples/operf.log for details.
>       >       Lowering the sampling rate may reduce or eliminate lost samples.
>       >       See the '--events' option description in the operf man page for help.
>       >       Profiling done.
>       >
>       >       $ opreport
>       >       Using /root/oprofile_data/samples/ for samples directory.
>       >       WARNING: Lost samples detected! See /root/oprofile_data/samples/operf.log for details.
>       >       CPU: Core 2, speed 2267 MHz (estimated)
>       >       Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit mask of 0x00 (Unhalted
>       core cycles) count 10000
>       >       CPU_CLK_UNHALT...|
>       >         samples|      %|
>       >       ------------------
>       >             429 100.000 ls
>       >             CPU_CLK_UNHALT...|
>       >               samples|      %|
>       >               ------------------
>       >                     313 72.9604 kallsyms
>       >                      55 12.8205 ld-2.19.so
>       >                      34  7.9254 libc-2.19.so
>       >                      17  3.9627 ls
>       >                       8  1.8648 ext4
>       >                       2  0.4662 binfmt_misc
>       >
>       >       You see that both operf and opreport warned about lost samples which means
>       >       that the overhead in kernel was too high and some samples were lost. But
>       >       probably not that many, since you see that I got 429 samples instead of
>       >       37 which is very roughly 10 times more.
>       >
>       >
>       >       Profiling is not for exact measurement of how many CPU ticks happened in
>       >       a function, it is rather designed for relative comparison across your code.
>       >
>       >       If you are getting too few samples, try to decrease the sample rate as I
>       >       did in the example. Have a look at `ophelp` what is the lowest value for
>       >       your event.
>       >
>       >       Also please note that the min sample rates are rough and depend on the load,
>       >       so under low load, lower rates can be used without issues. When you profile
>       >       systemwide on all CPUs, it's very high chance that you'll run into an overhead
>       >       and lose many samples...
>       >
>       >       I hope I explained it a bit.
>       >
>       >       Cheers,
>       >       Michael
>       >
>       >       > Thanks,
>       >       >
>       >       > Dhara Buch
>       >       >
>       >       >
>       >
>       >
>       >
>       >
> 
> 
> 
>

OProfile-1.2.0-rc2

[William Cohen <wcohen@re...>]

Due to some fixes for "make check" made oprofile-1.2.0-rc2.tar.gz. Proposed fixes to address the rapid thread spawning  are not this release.

URL:
https://sourceforge.net/projects/oprofile/files/oprofile/oprofile-1.2.0rc2/oprofile-1.2.0rc2.tar.gz/download
 
RELEASE NOTES:


OProfile is a powerful system-wide profiler for Linux.
Read more at http://oprofile.sf.net

OProfile 1.2.0 has been released.

New features
------------

- New/updated Processor Support
    * ARM Cortex A17
    * IBM Power 9
    * IBM Power 8NV and NVL variants
    * IBM z13
    * Intel Goldmont
    * Intel Kabylake
    * Intel Xeon Phi (Knights Landing)
    * Achitecture specific events for Applied Micro X-Gene

Bug fixes
---------

Filed bug reports:
-------------------------------------------------------------------------
|  BUG ID   |  Summary 
|-----------|------------------------------------------------------------
|  286      | Compilation error: left shift of negative value
|  288      | oprofile fails to build with --enable-pch and gcc-6.2 
-------------------------------------------------------------------------

Other bug fixes and improvements without a filed report (e.g., posted to the lis
t):
---------------
   - Fixed compile warning and errors when using GCC 6 or GCC 7
   - Avoid using deprecated readdir_r function
   - Store samples in the archive and search the appropriate places
     for samples
   - Only start the application if the perf events setup was successful
   - Corrections in the code and i386 events so "make check" tests pass


Known problems and limitations
-------------------------

- When using operf to profile multiple events, the absolute number of
  events recorded may be substantially fewer than expected. This can
  be due to known bug in the Linux kernel's Performance Events
  Subsystem that was fixed sometime between Linux kernel version 3.1
  and 3.5.

- Monitoring processes that frequently create and destroy threads via
  the "--pid" option can be problematic.  The pipes used within operf
  and ocount may fill up can cause these programs to hang and require
  multiple cntl-C to exit rather than successfully collecting data on
  fast spawning processes and children.

Re: Operf and Opreport outputs

[dhara buch <dharabuchphd@gm...>]

Hello,

I tried the perf-hello.c file and found the results as you explained. It is
very helpful to me. Now, for PERF_COUNT_HW_BRANCH_MISSES, I am getting
varying values every time unlike PERF_COUNT_HW_INSTRUCTIONS.

To get count for only defined process, I am trying to set perf_event_attr
structure variables sample_type as PERF_SAMPLE_BRANCH_STACK and
branch_sample_type as PERF_SAMPLE_BRANCH_USER. By doing so, I am getting
error no. 5 by perf_event_open. What may be the problem?

Dhara Buch

On Mon, Jun 19, 2017 at 5:51 PM, Michael Petlan <mpetlan@...> wrote:

> On Mon, 19 Jun 2017, dhara buch wrote:
> > Hello,
> > Thanks a lot for the detailed explanation. I could understand the
> working of operf and opreport.
> > Unlike operf, ocount counts each occurrence of the monitored event. In
> such a case, why ocount also gives varying values of CPU_CLK_UNHALTED even
> when the monitored code doesn't get
> > changed. Is it because of background processes? If so, then can we get
> event count for only monitored command?
>
> Hi Dhara,
>
> it is kind of because of the background processes, but not in the way that
> ocount
> would count also their CPU consumption. If you don't use '-s' option,
> ocount will
> count only what your command does.
>
> However, it counts either kernelspace, userspace or both (default if you
> are root).
> This can be configured by the event's flags:
>
> Both:
> -e CPU_CLK_UNHALTED:0:1:1
>
> Only kernelspace (used by the command, i.e. syscalls, etc):
> -e CPU_CLK_UNHALTED:0:1:0
>
> Only userspace (i.e. syscalls are excluded):
> -e CPU_CLK_UNHALTED:0:0:1
>
> (the format is (ocount): event:umask:kernelspace:userspace,
> for operf it is: event:umask:sample_rate:kernelspace:userspace)
>
> The numbers are slightly different each run because the process does not
> live in
> vacuum. It is usually dynamically linked, it calls libraries, kernel
> switches
> contexts, etc. All these things cause the differences. Also, the CPU
> optimizes
> the execution with floating success, depending on what else runs there
> with it.
> If the process is interrupted many times, the CPU consumption will be
> higher.
>
> I have a sample code which I linked dynamically and statically. While the
> dyn.
> linked executable always takes around 670,260 cycles, the statically
> linked one
> takes around 380,202 and seems to be more steady. Since it is very simple
> code,
> you can see that the linker-related stuff took more than 40% of the CPU
> cycles).
>
> Executing a binary is so complex problem that there is no surprise that
> those
> measurements give different values every time.
>
> ........
>
> TIP:
>
> You can use either papi library or the built-in kernel support for counting
> just a particular part of code, e.g. a function. I have attached one
> example
> which uses perfevents kernel background. I have two functions for factorial
> counting, one is slightly less effective than the other. I count cycles and
> instructions for both. When executing repeatedly, you can see, that the
> inst.
> count is the same all the time (at least on my laptop), but the cycles
> count
> differs even for just the stuff in the functions which are very simple.
>
> cc -o perf-hello perf-hello.c myperf.c
> ./perf-hello
>
> Ineffective method:
>         PERF_COUNT_HW_CPU_CYCLES = 32192
>         PERF_COUNT_HW_INSTRUCTIONS = 20681
>
> More effective method:
>         PERF_COUNT_HW_CPU_CYCLES = 15931
>         PERF_COUNT_HW_INSTRUCTIONS = 19103
>
> ........
>
> Cheers,
> Michael
>
>
> >
> > Thank you,
> >
> > On Fri, Jun 16, 2017 at 4:52 PM, Michael Petlan <mpetlan@...>
> wrote:
> >       On Fri, 16 Jun 2017, dhara buch wrote:
> >       > Hello,
> >       >
> >       > Many days ago you had helped me a lot in using Oprofile in
> Virtual Machine. That time, I also had a query regarding
> >       > getting information from 'opreport --symbols --debuginfo'
> command.
> >
> >       Hello,
> >
> >       yeah, I remember...
> >
> >       >
> >       > Actually, I am profiling a file1.c file with the following
> commands...
> >       >
> >       > 1. gcc -g file1.c -o file1
> >       >
> >       > 2. operf ./file1 --events=CPU_CLK_UNHALTED
> >       >
> >       > 3. opreport --symbols --debuginfo
> >       >
> >       > the output contains various lines where one line look follows:
> >       >
> >       > samples  %        linenr info                 image
> name               symbol name
> >       >
> >       > 2       12.5000  rsaimp.c:16
> rsaimp                   MM
> >       > 2        12.5000  rsaimp.c:34
> rsaimp                   main
> >       >
> >       > When I execute commands 2 and 3 multiple times, each time I gwt
> the output for symbole name MM (which is UDF in the
> >       > program) but I don't get output for main every time.
> >       >
> >       This is kind of random, see below.
> >
> >       > Additionally,'' the sample % also vary every time I file operf
> command. I do not understand the working of operf that
> >       > how it gives different outputs for the same program.
> >       >
> >
> >       How _counting_ works:
> >
> >       Each time an event happens in CPU (in our case -- CPU_CLK_UNHALTED
> -- one
> >       CPU tick), its counter is incremented by one. This way, you can
> get the
> >       whole number of how many times the event happened:
> >
> >       $ ocount ls
> >       Events were actively counted for 1863267 nanoseconds.
> >       Event counts (actual) for /bin/ls:
> >                 Event                    Count                    % time
> counted
> >                 CPU_CLK_UNHALTED         2,672,309                100.00
> >
> >       This means that there were 2.672 million CPU ticks necessary to
> execute
> >       `ls`.
> >
> >       The tool for counting is *ocount*.
> >
> >
> >       How _profiling_ works:
> >
> >       For profiling, events are counted the same way as when counting,
> but only
> >       once per N event occurrences a "sample" is taken. A sample is a
> piece of
> >       information about where in the code it happened, what was the
> context and
> >       potentially call-stack, etc. This sample is saved into the
> oprofile_data
> >       dir structure. When you finish profiling, opreport generates some
> overview
> >       from the samples recorded.
> >
> >       Of course, taking sample causes some overhead. Thus, you cannot
> take it
> >       each time the event counter increments. For this purpose, there is
> "sample
> >       rate" value which divides the event counter and takes a sample
> only once
> >       per "sample rate" occurrences. Thus, it is pretty random, which
> event
> >       occurrence is picked for a sample.
> >
> >       Of course, your main() consumes CPU ticks and the counter is
> incremented,
> >       but sometimes, one of these incrementations produces sample,
> sometimes not,
> >       thus the function is missing.
> >
> >       You have 2 samples on each of the line in the report. That is
> really a low
> >       number, so it is very probable that sometimes the samples hit
> main() and
> >       sometimes not.
> >
> >       $ operf ls
> >       Profiling done.
> >
> >       $ opreport
> >       Using /root/oprofile_data/samples/ for samples directory.
> >       CPU: Core 2, speed 2267 MHz (estimated)
> >       Counted CPU_CLK_UNHALTED events (Clock cycles when not halted)
> with a unit mask of 0x00 (Unhalted core cycles) count 100000
> >       CPU_CLK_UNHALT...|
> >         samples|      %|
> >       ------------------
> >        -->   37 100.000 ls
> >              CPU_CLK_UNHALT...|
> >                samples|      %|
> >                        ------------------
> >                     27 72.9730 kallsyms
> >                      5 13.5135 libc-2.19.so
> >                      2  5.4054 ld-2.19.so
> >                      1  2.7027 ls
> >                      1  2.7027 ext4
> >                      1  2.7027 libattr.so.1.1.0
> >
> >       You see that out of (estimated) 2.5-3.5 mil of event occurrences
> (which is
> >       the scale `ls` usually needs on my PC), I got only 37 samples.
> >
> >       The sample rate for each event are in `ophelp` as "min count".
> >
> >       Why did I get 37 samples? My default setting of default event is:
> >
> >       $ ophelp -d
> >       CPU_CLK_UNHALTED:100000:0:1:1
> >       -------------------^^
> >
> >       This means that there is 1 sample per 100000 event occurrences.
> >
> >       You can tweak this value a bit, but note that oprofile won't let
> you set
> >       the value to be too low, due to the overhead reasons.
> >
> >       Let's try 10000 (sampling 10 times more often):
> >
> >       $ operf -e CPU_CLK_UNHALTED:10000 ls
> >       WARNING: Lost samples detected! See /root/oprofile_data/samples/operf.log
> for details.
> >       Lowering the sampling rate may reduce or eliminate lost samples.
> >       See the '--events' option description in the operf man page for
> help.
> >       Profiling done.
> >
> >       $ opreport
> >       Using /root/oprofile_data/samples/ for samples directory.
> >       WARNING: Lost samples detected! See /root/oprofile_data/samples/operf.log
> for details.
> >       CPU: Core 2, speed 2267 MHz (estimated)
> >       Counted CPU_CLK_UNHALTED events (Clock cycles when not halted)
> with a unit mask of 0x00 (Unhalted core cycles) count 10000
> >       CPU_CLK_UNHALT...|
> >         samples|      %|
> >       ------------------
> >             429 100.000 ls
> >             CPU_CLK_UNHALT...|
> >               samples|      %|
> >               ------------------
> >                     313 72.9604 kallsyms
> >                      55 12.8205 ld-2.19.so
> >                      34  7.9254 libc-2.19.so
> >                      17  3.9627 ls
> >                       8  1.8648 ext4
> >                       2  0.4662 binfmt_misc
> >
> >       You see that both operf and opreport warned about lost samples
> which means
> >       that the overhead in kernel was too high and some samples were
> lost. But
> >       probably not that many, since you see that I got 429 samples
> instead of
> >       37 which is very roughly 10 times more.
> >
> >
> >       Profiling is not for exact measurement of how many CPU ticks
> happened in
> >       a function, it is rather designed for relative comparison across
> your code.
> >
> >       If you are getting too few samples, try to decrease the sample
> rate as I
> >       did in the example. Have a look at `ophelp` what is the lowest
> value for
> >       your event.
> >
> >       Also please note that the min sample rates are rough and depend on
> the load,
> >       so under low load, lower rates can be used without issues. When
> you profile
> >       systemwide on all CPUs, it's very high chance that you'll run into
> an overhead
> >       and lose many samples...
> >
> >       I hope I explained it a bit.
> >
> >       Cheers,
> >       Michael
> >
> >       > Thanks,
> >       >
> >       > Dhara Buch
> >       >
> >       >
> >
> >
> >
> >
>

Re: Fwd: Potential deadlock in operf when using --pid

[William Cohen <wcohen@re...>]

On 06/24/2016 08:06 PM, 大平怜 wrote:
> I forgot to include oprofile-list.
> 
> 
> Regards,
> Rei Odaira
> 
> ---------- Forwarded message ----------
> From: *大平怜* <rei.odaira@... <mailto:rei.odaira@...>>
> Date: 2016-06-24 19:04 GMT-05:00
> Subject: Re: Potential deadlock in operf when using --pid
> To: William Cohen <wcohen@... <mailto:wcohen@...>>
> 
> 
> Hi,
> 
> Now I come back to this problem.
> 
> I am attaching two patches to solve it.  They apply to the latest master in the git repository.  Please apply oprofile_avoid_deadlock_1.patch first and then oprofile_avoid_deadlock_2.patch. The first patch is just for refactoring the code to make the second patch possible, and the second patch is for the actual problem solving.
> 
> So, the problem is that the operf-record process is blocked on a write to the sample output pipe when the pipe is full, while the operf-read process, which is the consumer of the pipe, cannot read from the pipe because it is blocked on a read from the comm pipe, to which the operf-record process is supposed to write.  Please refer to the previous emails for the detailed problem description.
> 
>             |<--sample output pipe--|
> operf-read  |-------comm pipe------>|  operf-record
>             |<------comm pipe-------|
> 
> My solution is to make the sample output pipe non-blocking on the operf-record side.  When the sample output pipe is full, instead of waiting on it, the operf-record process polls both the sample output pipe and the (read-end of) comm pipe.  If there is a message in the comm pipe from the operf-read process, the operf-record process handles it and writes a response to the comm pipe, so that the operf-read process can finish being blocked on the read from the comm pipe and eventually can consume the sample output pipe.
> 
> There are some other ways to solve this problem, so any comments are welcome.  With my patches, you can finish profiling oprofile_multithread_test by a single ctrl-c. They passed all the tests in oprofile-tests.
> 
> 
> Regards,
> Rei Odaira
> 




Hi Da Rei,

Sorry for missing the patches to address rapid thread
creation/deletion deadlock issue.  I have been taking a look at them.
As a sanity check I ran the testsuite before and after the patches and
things look the same.

Test results before the patches:

		=== oprofile Summary ===

# of expected passes		149

kernel version: 4.11.5-200.fc25.x86_64
userspace version: oprofile 1.2.0git compiled on Jun 29 2017 13:59:35


Test results after the patches:

		=== oprofile Summary ===

# of expected passes		149

kernel version: 4.11.5-200.fc25.x86_64
userspace version: oprofile 1.2.0git compiled on Jun 29 2017 14:10:33


The patches does appear to help with the issue demonstrated with the
reporducer oprofile_mutithread_test with operations per thread of
1000000.  However, with smaller number of operations per thread
settings (100000) operf has issue getting connected:

$ operf --pid 7555
!!!! No samples collected !!!
The target program/command ended before profiling was started.
operf record init failed
usage: operf [ options ] [ --system-wide | --pid <pid> | [ command [ args ] ] ]
Error running profiler


Or if it is able to connect (the process was paused with cntl-z and
then put back in the foreground after oprofile had attached):

$ operf --pid 7555
...
Unable to collect samples for forked process 17240. Process may have ended before recording could be started.
Unable to collect samples for forked process 17241. Process may have ended before recording could be started.
Unable to collect samples for forked process 17242. Process may have ended before recording could be started.
Unable to collect samples for forked process 17243. Process may have ended before recording could be started.
Failed to mmap kernel profile data.
This issue may be caused by a non-root user running multiple operf
sessions simultaneously. Try running as root or increasing the value of
/proc/sys/kernel/perf_event_mlock_kb to resolve the problem.

Unable to collect samples for forked process 17245. Process may have ended before recording could be started.


Is is notable that perf has similar problems it is unable to attach to quickly spawning processes

$ perf record --pid 7555
Error:
The sys_perf_event_open() syscall returned with 3 (No such process) for event (cycles).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?
[wcohen@... oprofile]$ perf record --pid 7555
^C[ perf record: Woken up 81 times to write data ]

However "perf record --pid 7555" is able to collect data without issue
if the 7555 is paused when "perf record" starts up.  I have let the
perf developers know about this issue.


The portion of oprofile the patches affect is not easy to follow, so I
am still trying to make sure I fully understand the issue and that the
patches address the issue without introducing some other issue.
Earlier email has the following diagram:


            |<--sample output pipe--|
operf-read  |-------comm pipe------>|  operf-record
            |<------comm pipe-------|


The data in the sample "sample output pipe" stream includes the
PERF_RECORD_FORK events.  The operf-read processes the
PERF_RECORD_FORK events in the stream and sends pid back up the comm
pipe for operf-record add another thread.

Is the comm pipe only being used to communicate the new processes to be monitored?

Would it be possible to have operf-record just do that directly rather
than having to make a round trip from operf-record to operf-read and
back to operf-record?  Seems like there is a lot of overhead when
starting to monitoring a new thread.

The patches implement polling to avoid the opef-record getting hung
and in turn causing operf-read getting stuck when sample output pipe
gets full.  Is there any way that the comm pipe might similarly get
full and cause a hang?

-Will

Re: OProfile-1.2.0-rc1

[Will Schmidt <will_schmidt@vn...>]

On Wed, 2017-06-28 at 12:08 -0400, William Cohen wrote:
> On 06/28/2017 11:53 AM, William Cohen wrote:
> > On 06/26/2017 10:42 AM, Will Schmidt wrote:
> >> On Mon, 2017-06-19 at 11:08 -0400, William Cohen wrote:
> >>> There have been a number of improvements checked into the OProfile git repo.  It would be good to have those into an official release.  I have made a release candidate and it would be good to test this out on various platforms.
> >>>
> >>> URL:
> >>> https://sourceforge.net/projects/oprofile/files/oprofile/oprofile-1.2.0rc1/oprofile-1.2.0rc1.tar.gz/download
> >>>
> >>
> >> I grabbed and did a build/run across a small assortment of power
> >> systems.   (power7,power8LE,power8BE), test suite runs clean. 
> >> (Also looks good on pre-ga P9)
> >> 			=== oprofile Summary ===
> >> 	
> >> 	# of expected passes		78
> >>
> >> One error in 'make check'.  (also see this on my x86 laptop).
> >> I suspect not a big deal, but in case... :-)
> >>
> >> 	FAIL: load_events_files_tests
> >>
> >> 	um zero is not used
> >>
> >> A quick peek via gdb suggests this is occurring when trying to parse the
> >> events files for CPU_CORE_I7, down the op_events(cpu_type) path.  If I
> >> force that test to pass via setting err=0 in gdb, it occurs again on
> >> CPU_NEHALEM.
> >>
> >> Breakpoint 1, op_events (cpu_type=CPU_CORE_I7) at op_events.c:724
> >> 724	{
> >> $60 = CPU_CORE_I7
> >> um zero is not used
> >>
> >> Breakpoint 1, op_events (cpu_type=CPU_NEHALEM) at op_events.c:724
> >> 724	{
> >> $63 = CPU_NEHALEM
> >> um zero is not used
> >>
> >>
> >> thanks
> >> -Will (Schmidt)
> > 
> > Hi Will,
> > 
> > I took a look at this failure from "make check".  This is due to the events/i386/arch_perfmon/unit_masks having the unit mask zero, but it not being used in nahelem for the events. i386/nehalem/events has:
> > 
> > #event:0x3c counters:0,1,2,3 um:zero minimum:6000 name:CPU_CLK_UNHALTED : Clock cycles when not halted
> > event:0x3c counters:0,1,2,3 um:one minimum:6000 name:UNHALTED_REFERENCE_CYCLES : Unhalted reference cycles
> > 
> > The nahelem events are included in the i386/core_i7 events. Thus, it also suffers from the same problem.  This appears to be relatively harmless.  However, it does cause the load_events_files_tests test to abort so processors after core_i7 (including nehalem) are not check for event sanity.  I manually set err=0 after each of the reports of the unused mask and didn't see any other problems.
> > 
> > -Will Cohen
> 
> The attached patch should address the test failure.  Does that seem like a reasonable fix?  -Will

Looks good to me.   fixes the problem, at least. :-)


PASS: cpu_type_tests
PASS: parse_event_tests
PASS: load_events_files_tests
PASS: alloc_counter_tests
PASS: mangle_tests
PASS: utf8_checker.sh
============================================================================
Testsuite summary for OProfile 1.2.0rc1
============================================================================
# TOTAL: 6
# PASS:  6
# SKIP:  0
# XFAIL: 0
# FAIL:  0
# XPASS: 0
# ERROR: 0

Re: OProfile-1.2.0-rc1

[William Cohen <wcohen@re...>]

On 06/28/2017 11:53 AM, William Cohen wrote:
> On 06/26/2017 10:42 AM, Will Schmidt wrote:
>> On Mon, 2017-06-19 at 11:08 -0400, William Cohen wrote:
>>> There have been a number of improvements checked into the OProfile git repo.  It would be good to have those into an official release.  I have made a release candidate and it would be good to test this out on various platforms.
>>>
>>> URL:
>>> https://sourceforge.net/projects/oprofile/files/oprofile/oprofile-1.2.0rc1/oprofile-1.2.0rc1.tar.gz/download
>>>
>>
>> I grabbed and did a build/run across a small assortment of power
>> systems.   (power7,power8LE,power8BE), test suite runs clean. 
>> (Also looks good on pre-ga P9)
>> 			=== oprofile Summary ===
>> 	
>> 	# of expected passes		78
>>
>> One error in 'make check'.  (also see this on my x86 laptop).
>> I suspect not a big deal, but in case... :-)
>>
>> 	FAIL: load_events_files_tests
>>
>> 	um zero is not used
>>
>> A quick peek via gdb suggests this is occurring when trying to parse the
>> events files for CPU_CORE_I7, down the op_events(cpu_type) path.  If I
>> force that test to pass via setting err=0 in gdb, it occurs again on
>> CPU_NEHALEM.
>>
>> Breakpoint 1, op_events (cpu_type=CPU_CORE_I7) at op_events.c:724
>> 724	{
>> $60 = CPU_CORE_I7
>> um zero is not used
>>
>> Breakpoint 1, op_events (cpu_type=CPU_NEHALEM) at op_events.c:724
>> 724	{
>> $63 = CPU_NEHALEM
>> um zero is not used
>>
>>
>> thanks
>> -Will (Schmidt)
> 
> Hi Will,
> 
> I took a look at this failure from "make check".  This is due to the events/i386/arch_perfmon/unit_masks having the unit mask zero, but it not being used in nahelem for the events. i386/nehalem/events has:
> 
> #event:0x3c counters:0,1,2,3 um:zero minimum:6000 name:CPU_CLK_UNHALTED : Clock cycles when not halted
> event:0x3c counters:0,1,2,3 um:one minimum:6000 name:UNHALTED_REFERENCE_CYCLES : Unhalted reference cycles
> 
> The nahelem events are included in the i386/core_i7 events. Thus, it also suffers from the same problem.  This appears to be relatively harmless.  However, it does cause the load_events_files_tests test to abort so processors after core_i7 (including nehalem) are not check for event sanity.  I manually set err=0 after each of the reports of the unused mask and didn't see any other problems.
> 
> -Will Cohen

The attached patch should address the test failure.  Does that seem like a reasonable fix?  -Will