DSO_BINARY_TYPE__SYSTEM_PATH_DSO

DSO_BINARY_TYPE__SYSTEM_PATH_DSO

[Rajasekhar Pulluru]

Hi Team,
Could someone help me shed some light on this macro
DSO_BINARY_TYPE__SYSTEM_PATH_DSO ?

Case-1: I am trying to run perf top -p `pidof <app>` on ubuntu host
(based on ubuntu:jammy, outside the container) where the <app> runs
inside a container that's based on ubuntu bionic, and I don't see any
of <app> symbols (only hex-address and no function names) in perf top
output.

Case-2: When I try to run perf top -p `pidof <app>` on ubuntu host
(based on ubuntu:bionic, outside the container) where the <app> runs
inside a container that's also based on ubuntu bionic, and I can see
<app> symbols (function names) in perf top output.

On debugging both the cases, I find that, case-2 is able to display
symbol when dso__load of </opt/bin/<app> is successful for the type
DSO_BINARY_TYPE__SYSTEM_PATH_DSO, where-as the same fails for case-1
(is_regular_file check fails), and perf top reports "Failed to open
/opt/bin/<app>, continuing without symbols".

In both the cases, the file /opt/bin/<app> is not available on the
host, and its only available inside the container.
What could be causing the above failure?

Appreciate any help/inputs.

Thanks & Regards,
Rajasekhar

Re: DSO_BINARY_TYPE__SYSTEM_PATH_DSO

[Ian Rogers]

On Fri, May 19, 2023 at 10:49 AM Rajasekhar Pulluru
<pullururajasekhar@gmail.com> wrote:
>
> Hi Team,
> Could someone help me shed some light on this macro
> DSO_BINARY_TYPE__SYSTEM_PATH_DSO ?
>
> Case-1: I am trying to run perf top -p `pidof <app>` on ubuntu host
> (based on ubuntu:jammy, outside the container) where the <app> runs
> inside a container that's based on ubuntu bionic, and I don't see any
> of <app> symbols (only hex-address and no function names) in perf top
> output.
>
> Case-2: When I try to run perf top -p `pidof <app>` on ubuntu host
> (based on ubuntu:bionic, outside the container) where the <app> runs
> inside a container that's also based on ubuntu bionic, and I can see
> <app> symbols (function names) in perf top output.
>
> On debugging both the cases, I find that, case-2 is able to display
> symbol when dso__load of </opt/bin/<app> is successful for the type
> DSO_BINARY_TYPE__SYSTEM_PATH_DSO, where-as the same fails for case-1
> (is_regular_file check fails), and perf top reports "Failed to open
> /opt/bin/<app>, continuing without symbols".
>
> In both the cases, the file /opt/bin/<app> is not available on the
> host, and its only available inside the container.
> What could be causing the above failure?
>
> Appreciate any help/inputs.

Hi Rajasekhar,

This is an area I'm not familiar with. I suspect the reason perf
record/report are succeeding from your description is namespace
information. If you look at the perf.data file with "perf script" and
probably the "-D" option, you should see information. I'm not sure
anybody has wired up the namespace code with perf top, which would go
a long way to explaining your problems.

Thanks for investigating this!
Ian

> Thanks & Regards,
> Rajasekhar

Re: DSO_BINARY_TYPE__SYSTEM_PATH_DSO

[Rajasekhar Pulluru]

Hi Ian,
Thanks for responding, I really appreciate your time and help!

Sorry, I don't see namespace related information in perf script output
(with/without -D option).
I tried to explore other options, but was not able to find an option
that can dump the ns information.

Do you have any alternate suggestions to debug this?

Thanks & Regards,
Rajasekhar

On Fri, May 19, 2023 at 11:27 PM Ian Rogers <irogers@google.com> wrote:
>
> On Fri, May 19, 2023 at 10:49 AM Rajasekhar Pulluru
> <pullururajasekhar@gmail.com> wrote:
> >
> > Hi Team,
> > Could someone help me shed some light on this macro
> > DSO_BINARY_TYPE__SYSTEM_PATH_DSO ?
> >
> > Case-1: I am trying to run perf top -p `pidof <app>` on ubuntu host
> > (based on ubuntu:jammy, outside the container) where the <app> runs
> > inside a container that's based on ubuntu bionic, and I don't see any
> > of <app> symbols (only hex-address and no function names) in perf top
> > output.
> >
> > Case-2: When I try to run perf top -p `pidof <app>` on ubuntu host
> > (based on ubuntu:bionic, outside the container) where the <app> runs
> > inside a container that's also based on ubuntu bionic, and I can see
> > <app> symbols (function names) in perf top output.
> >
> > On debugging both the cases, I find that, case-2 is able to display
> > symbol when dso__load of </opt/bin/<app> is successful for the type
> > DSO_BINARY_TYPE__SYSTEM_PATH_DSO, where-as the same fails for case-1
> > (is_regular_file check fails), and perf top reports "Failed to open
> > /opt/bin/<app>, continuing without symbols".
> >
> > In both the cases, the file /opt/bin/<app> is not available on the
> > host, and its only available inside the container.
> > What could be causing the above failure?
> >
> > Appreciate any help/inputs.
>
> Hi Rajasekhar,
>
> This is an area I'm not familiar with. I suspect the reason perf
> record/report are succeeding from your description is namespace
> information. If you look at the perf.data file with "perf script" and
> probably the "-D" option, you should see information. I'm not sure
> anybody has wired up the namespace code with perf top, which would go
> a long way to explaining your problems.
>
> Thanks for investigating this!
> Ian
>
> > Thanks & Regards,
> > Rajasekhar