Re: Oprofile Report

[dhara buch <dharabuchphd@gmail.com>]

[-- Attachment #1.1: Type: text/plain, Size: 3723 bytes --]

Hi,

Yes, when I try to execute 'opreport --symbols --debug-info' command after
doing profiling for a .c file (let operf ./test),

I am expecting 'test.c:line_no' in linear info field as you are getting
'exact_counts.c:13' in the following:

samples %        linenr info                 image name
 symbol name
10       66.6667  (no location information)   no-vmlinux
 /no-vmlinux
2        13.3333  *exact_counts.c:13*           exact_counts
 main
1         6.6667  *exact_counts.c:10*           exact_counts
 f_65535x
1         6.6667  *exact_counts.c:9*            exact_counts
 f_997x
1         6.6667  (no location information)   ld-2.17.so
 _dl_fini

I tried to install debuginfo using
#debuginfo-install kernel command.

But when I execute 'opreport --symbols --debug-info', I get only (no
location information)  in all of my samples.

What may be the reason?

On Thu, Mar 23, 2017 at 8:08 PM, Michael Petlan <mpetlan@redhat.com> wrote:

> On Thu, 23 Mar 2017, dhara buch wrote:
>
>> Hello,
>> I am doing profiling with command,
>>
>> operf ./test --events=BR_INST_RETIRED
>> where test.c is a simple c language file.
>>
>> then, I am trying to collect information with command
>>
>> opreport --symbols --debug-info
>>
>> From the documents of Oprofile, I assume that the above command lists
>> profiling result as per the symbols i.e. I can get result showing samples,
>> linear info, image name and symbol name.
>>
>> As per my command I expect my file name (test.c) to be in the linear info
>> and image name, but shows [no location information] in linear info. The
>> filename does not get listed in image
>> name also.
>>
>> What is lacking?
>>
>
> Hi, I think you need to rebuild the test with '-g' switch.
> If the test binary does not have debuginfo, opreport cannot
> resolve that.
>
> Me trying with debuginfo:
>
> samples  %        linenr info                 image name
>  symbol name
> 10       66.6667  (no location information)   no-vmlinux
>  /no-vmlinux
> 2        13.3333  exact_counts.c:13           exact_counts             main
> 1         6.6667  exact_counts.c:10           exact_counts
>  f_65535x
> 1         6.6667  exact_counts.c:9            exact_counts
>  f_997x
> 1         6.6667  (no location information)   ld-2.17.so
>  _dl_fini
>
> And without:
>
> samples  %        linenr info                 image name
>  symbol name
> 10       55.5556  (no location information)   no-vmlinux
>  /no-vmlinux
> 3        16.6667  (no location information)   exact_counts
>  f_65535x
> 2        11.1111  (no location information)   exact_counts             main
> 1         5.5556  (no location information)   ld-2.17.so
>  _dl_add_to_slotinfo
> 1         5.5556  (no location information)   ld-2.17.so
>  _dl_next_tls_modid
> 1         5.5556  (no location information)   ld-2.17.so
>  _dl_relocate_object
>
> Is this the problem you are asking about?
>
>
>> I tried to set vmlinux with operf --vmlinux option also where vmlinux
>> file in in /usr/lib/debug/lib/4*/vmlinux, still the above commands do not
>> list test file entries.
>>
>
> The "--vmlinux" option is there for enabling this for samples
> obtained in kernelspace.
>
> By default (assuming you have no kernel debuginfo available),
> operf marks all the samples taken in kernel (e.g. your program
> called a syscall and the sample was taken when the syscall was
> being executed or you profile systemwide) as "no-vmlinux".
>
> This is sufficient if you care about userspace only and not about
> the "time" spent in kernel.
>
> If you care about kernelspace, you need the '--vmlinux' option
> with correct path specified.
>
>
>> What is lacking?
>>
>> Thank you,
>>
>> Dhara buch
>>
>>
>>
> Has this helped?
>
> Cheers,
> Michael
>
>

[-- Attachment #1.2: Type: text/html, Size: 6642 bytes --]

[-- Attachment #2: Type: text/plain, Size: 127 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel