How to build lttng on RHEL 9?

How to build lttng on RHEL 9?

[David Aldrich via lttng-dev]

Hi

I have a build error for lttng-modules-2.14.3 on RHEL 9.6:

lttng-modules-2.14.3/src/lttng-statedump-impl.c:408:20: error:
‘dev_base_lock’ undeclared (first use in this function); did you mean
‘device_lock’?
  408 |         read_lock(&dev_base_lock);
      |                    ^~~~~~~~~~~~~

Please can you advise me how to fix this?

(I am only building from source because I assume lttng packages aren't
available for RHEL 9).

Thanks in advance
David

Re: How to build lttng on RHEL 9?

[Kienan Stewart via lttng-dev]

Hi David,

RHEL kernels often backport a variety of changes. It is likely that 
lttng-modules needs to be updated for the exact kernel you're building 
for, which is usually just updating version range checks similar to this[1].

Based on your error message, I think the version range check that needs 
to be updated is here[2].

What's the exact version number of the kernel you're trying to build for?

thanks,
kienan

[1]: 
https://github.com/lttng/lttng-modules/commit/924b0ab5ad13570c4d4a305839684b37538064d7
[2]: 
https://github.com/lttng/lttng-modules/blob/b1a23b9733ce6217659bc5e62961d128794a2beb/src/lttng-statedump-impl.c#L389




On 1/19/26 11:00 AM, David Aldrich via lttng-dev wrote:
> Hi
> 
> I have a build error for lttng-modules-2.14.3 on RHEL 9.6:
> 
> lttng-modules-2.14.3/src/lttng-statedump-impl.c:408:20: error:
> ‘dev_base_lock’ undeclared (first use in this function); did you mean
> ‘device_lock’?
>    408 |         read_lock(&dev_base_lock);
>        |                    ^~~~~~~~~~~~~
> 
> Please can you advise me how to fix this?
> 
> (I am only building from source because I assume lttng packages aren't
> available for RHEL 9).
> 
> Thanks in advance
> David

Re: How to build lttng on RHEL 9?

[David Aldrich via lttng-dev]

Hi Kienan

> What's the exact version number of the kernel you're trying to build for?

Thanks for your reply. Our kernel version is:

$ uname -r
5.14.0-570.60.1.el9_6.x86_64

David

Re: How to build lttng on RHEL 9?

[David Aldrich via lttng-dev]

Hi Kienan

I have updated to the latest kernel version for RHEL 9.6, which is:

5.14.0-611.24.1.el9_7.x86_64

AI suggests 'RHEL 9.7 backported into its 5.14.z stream: dev_base_lock
was removed from the networking core' which I guess causes the
problem?

Is it possible to provide a fix for this?

Best regards
David

On Mon, Jan 19, 2026 at 5:14 PM David Aldrich
<david.aldrich.ntml@gmail.com> wrote:
>
> Hi Kienan
>
> > What's the exact version number of the kernel you're trying to build for?
>
> Thanks for your reply. Our kernel version is:
>
> $ uname -r
> 5.14.0-570.60.1.el9_6.x86_64
>
> David

Re: How to build lttng on RHEL 9?

[Michael Jeanson via lttng-dev]

On 2026-01-20 11:12, David Aldrich via lttng-dev wrote:
> Hi Kienan
> 
> I have updated to the latest kernel version for RHEL 9.6, which is:
> 
> 5.14.0-611.24.1.el9_7.x86_64
> 
> AI suggests 'RHEL 9.7 backported into its 5.14.z stream: dev_base_lock
> was removed from the networking core' which I guess causes the
> problem?
> 
> Is it possible to provide a fix for this?


This issue should be fixed in a further release of lttng-modules, if 
your requirements are time sensitive note that EfficiOS [1] provides 
commercial support for LTTng.

Regards,

Michael


[1] https://www.efficios.com