Debian 3.16.7-ckt9-2 issue with lttng-modules kmem probe

Debian 3.16.7-ckt9-2 issue with lttng-modules kmem probe

[Mathieu Desnoyers]

Hi Jon,

It appears that lttng-modules cannot build on the
Debian kernel 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt9-2 (2015-04-13)
x86_64 GNU/Linux.

It appears that their exported kmem.h header differs from
the upstream stable branch, but AFAIK there is no Debian-specific
version number available to distinguish between upstream stable
and the Debian kernel.

We have been hit by this in the past for Ubuntu kernels, and the
solution has been to introduce a UTS_UBUNTU_RELEASE_ABI define
into their kernels, which can be used to follow their own kernel
versions.

Do you think we could ask Debian to do the same ?

Thanks!

Mathieu

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

Re: Debian 3.16.7-ckt9-2 issue with lttng-modules kmem probe

[Jon Bernard]

* Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> Hi Jon,
> 
> It appears that lttng-modules cannot build on the
> Debian kernel 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt9-2 (2015-04-13)
> x86_64 GNU/Linux.
> 
> It appears that their exported kmem.h header differs from
> the upstream stable branch, but AFAIK there is no Debian-specific
> version number available to distinguish between upstream stable
> and the Debian kernel.

Indeed.  The only distinguishing characteristic I see is EXTRAVERSION
defined to '-ckt9'.  I haven't had a chance to try yet, but could that
be acceptable?

> We have been hit by this in the past for Ubuntu kernels, and the
> solution has been to introduce a UTS_UBUNTU_RELEASE_ABI define
> into their kernels, which can be used to follow their own kernel
> versions.
> 
> Do you think we could ask Debian to do the same ?

I'm happy to ask, the argument is certainly sound.

-- 
Jon

Re: Debian 3.16.7-ckt9-2 issue with lttng-modules kmem probe

[Mathieu Desnoyers]

----- Original Message -----
> * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> > Hi Jon,
> > 
> > It appears that lttng-modules cannot build on the
> > Debian kernel 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt9-2 (2015-04-13)
> > x86_64 GNU/Linux.
> > 
> > It appears that their exported kmem.h header differs from
> > the upstream stable branch, but AFAIK there is no Debian-specific
> > version number available to distinguish between upstream stable
> > and the Debian kernel.
> 
> Indeed.  The only distinguishing characteristic I see is EXTRAVERSION
> defined to '-ckt9'.  I haven't had a chance to try yet, but could that
> be acceptable?

No, because we need to do conditionals comparing numeric values
both in Makefiles and within C.

> 
> > We have been hit by this in the past for Ubuntu kernels, and the
> > solution has been to introduce a UTS_UBUNTU_RELEASE_ABI define
> > into their kernels, which can be used to follow their own kernel
> > versions.
> > 
> > Do you think we could ask Debian to do the same ?
> 
> I'm happy to ask, the argument is certainly sound.

Thanks!

Mathieu

> 
> --
> Jon
> 

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

Re: Debian 3.16.7-ckt9-2 issue with lttng-modules kmem probe

[Jon Bernard]

* Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> ----- Original Message -----
> > * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> > > Hi Jon,
> > > 
> > > It appears that lttng-modules cannot build on the
> > > Debian kernel 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt9-2 (2015-04-13)
> > > x86_64 GNU/Linux.
> > > 
> > > It appears that their exported kmem.h header differs from
> > > the upstream stable branch, but AFAIK there is no Debian-specific
> > > version number available to distinguish between upstream stable
> > > and the Debian kernel.
> > 
> > Indeed.  The only distinguishing characteristic I see is EXTRAVERSION
> > defined to '-ckt9'.  I haven't had a chance to try yet, but could that
> > be acceptable?
> 
> No, because we need to do conditionals comparing numeric values
> both in Makefiles and within C.
> 
> > 
> > > We have been hit by this in the past for Ubuntu kernels, and the
> > > solution has been to introduce a UTS_UBUNTU_RELEASE_ABI define
> > > into their kernels, which can be used to follow their own kernel
> > > versions.
> > > 
> > > Do you think we could ask Debian to do the same ?
> > 
> > I'm happy to ask, the argument is certainly sound.
> 
> Thanks!

No problem, bug filed: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=783259

There may be a workaround I can put into the debian package as
a short term fix, maybe a conditional patch depending on those differing
3.16 versions.  We'll see how the bug progresses and I'll keep you
posted.

-- 
Jon

Re: Debian 3.16.7-ckt9-2 issue with lttng-modules kmem probe

[Jon Bernard]

* Jon Bernard <jbernard@debian.org> wrote:
> * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> > ----- Original Message -----
> > > * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> > > > Hi Jon,
> > > > 
> > > > It appears that lttng-modules cannot build on the
> > > > Debian kernel 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt9-2 (2015-04-13)
> > > > x86_64 GNU/Linux.
> > > > 
> > > > It appears that their exported kmem.h header differs from
> > > > the upstream stable branch, but AFAIK there is no Debian-specific
> > > > version number available to distinguish between upstream stable
> > > > and the Debian kernel.
> > > 
> > > Indeed.  The only distinguishing characteristic I see is EXTRAVERSION
> > > defined to '-ckt9'.  I haven't had a chance to try yet, but could that
> > > be acceptable?
> > 
> > No, because we need to do conditionals comparing numeric values
> > both in Makefiles and within C.
> > 
> > > 
> > > > We have been hit by this in the past for Ubuntu kernels, and the
> > > > solution has been to introduce a UTS_UBUNTU_RELEASE_ABI define
> > > > into their kernels, which can be used to follow their own kernel
> > > > versions.
> > > > 
> > > > Do you think we could ask Debian to do the same ?
> > > 
> > > I'm happy to ask, the argument is certainly sound.
> > 
> > Thanks!
> 
> No problem, bug filed: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=783259
> 
> There may be a workaround I can put into the debian package as
> a short term fix, maybe a conditional patch depending on those differing
> 3.16 versions.  We'll see how the bug progresses and I'll keep you
> posted.

Right, so I'll take a look at making a package update to resolve the
issue and get that into the stable archive so that lttng is again
working in the new release.

Sorry about this, it didn't occur to me that an API change would happen
and so I didn't continue testing 3.16 updates.  I'll get this sorted.

-- 
Jon

Re: Debian 3.16.7-ckt9-2 issue with lttng-modules kmem probe

[Mathieu Desnoyers]

----- Original Message -----
> * Jon Bernard <jbernard@debian.org> wrote:
> > * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> > > ----- Original Message -----
> > > > * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> > > > > Hi Jon,
> > > > > 
> > > > > It appears that lttng-modules cannot build on the
> > > > > Debian kernel 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt9-2 (2015-04-13)
> > > > > x86_64 GNU/Linux.
> > > > > 
> > > > > It appears that their exported kmem.h header differs from
> > > > > the upstream stable branch, but AFAIK there is no Debian-specific
> > > > > version number available to distinguish between upstream stable
> > > > > and the Debian kernel.
> > > > 
> > > > Indeed.  The only distinguishing characteristic I see is EXTRAVERSION
> > > > defined to '-ckt9'.  I haven't had a chance to try yet, but could that
> > > > be acceptable?
> > > 
> > > No, because we need to do conditionals comparing numeric values
> > > both in Makefiles and within C.
> > > 
> > > > 
> > > > > We have been hit by this in the past for Ubuntu kernels, and the
> > > > > solution has been to introduce a UTS_UBUNTU_RELEASE_ABI define
> > > > > into their kernels, which can be used to follow their own kernel
> > > > > versions.
> > > > > 
> > > > > Do you think we could ask Debian to do the same ?
> > > > 
> > > > I'm happy to ask, the argument is certainly sound.
> > > 
> > > Thanks!
> > 
> > No problem, bug filed:
> > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=783259
> > 
> > There may be a workaround I can put into the debian package as
> > a short term fix, maybe a conditional patch depending on those differing
> > 3.16 versions.  We'll see how the bug progresses and I'll keep you
> > posted.
> 
> Right, so I'll take a look at making a package update to resolve the
> issue and get that into the stable archive so that lttng is again
> working in the new release.
> 
> Sorry about this, it didn't occur to me that an API change would happen
> and so I didn't continue testing 3.16 updates.  I'll get this sorted.

Surprise surprise! The fixes are pushed upstream in master and stable-2.6.

commit ffc696db884c44a49780bcd9e3b0f97ef82d2382
Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date:   Mon Apr 27 11:03:17 2015 -0400

    Fix: update get_pfnblock_flags_mask wrapper for debian kernels
    
    Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

commit 72e6c528aad2cdd1152af21258a5f84870155b41
Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date:   Mon Apr 27 10:57:34 2015 -0400

    Fix: discover Debian API
    
    Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

Enjoy :)

Thanks,

Mathieu

> 
> --
> Jon
> 

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

Re: Debian 3.16.7-ckt9-2 issue with lttng-modules kmem probe

[Jon Bernard]

* Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> ----- Original Message -----
> > * Jon Bernard <jbernard@debian.org> wrote:
> > > * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> > > > ----- Original Message -----
> > > > > * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> > > > > > Hi Jon,
> > > > > > 
> > > > > > It appears that lttng-modules cannot build on the
> > > > > > Debian kernel 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt9-2 (2015-04-13)
> > > > > > x86_64 GNU/Linux.
> > > > > > 
> > > > > > It appears that their exported kmem.h header differs from
> > > > > > the upstream stable branch, but AFAIK there is no Debian-specific
> > > > > > version number available to distinguish between upstream stable
> > > > > > and the Debian kernel.
> > > > > 
> > > > > Indeed.  The only distinguishing characteristic I see is EXTRAVERSION
> > > > > defined to '-ckt9'.  I haven't had a chance to try yet, but could that
> > > > > be acceptable?
> > > > 
> > > > No, because we need to do conditionals comparing numeric values
> > > > both in Makefiles and within C.
> > > > 
> > > > > 
> > > > > > We have been hit by this in the past for Ubuntu kernels, and the
> > > > > > solution has been to introduce a UTS_UBUNTU_RELEASE_ABI define
> > > > > > into their kernels, which can be used to follow their own kernel
> > > > > > versions.
> > > > > > 
> > > > > > Do you think we could ask Debian to do the same ?
> > > > > 
> > > > > I'm happy to ask, the argument is certainly sound.
> > > > 
> > > > Thanks!
> > > 
> > > No problem, bug filed:
> > > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=783259
> > > 
> > > There may be a workaround I can put into the debian package as
> > > a short term fix, maybe a conditional patch depending on those differing
> > > 3.16 versions.  We'll see how the bug progresses and I'll keep you
> > > posted.
> > 
> > Right, so I'll take a look at making a package update to resolve the
> > issue and get that into the stable archive so that lttng is again
> > working in the new release.
> > 
> > Sorry about this, it didn't occur to me that an API change would happen
> > and so I didn't continue testing 3.16 updates.  I'll get this sorted.
> 
> Surprise surprise! The fixes are pushed upstream in master and stable-2.6.
> 
> commit ffc696db884c44a49780bcd9e3b0f97ef82d2382
> Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Date:   Mon Apr 27 11:03:17 2015 -0400
> 
>     Fix: update get_pfnblock_flags_mask wrapper for debian kernels
>     
>     Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> 
> commit 72e6c528aad2cdd1152af21258a5f84870155b41
> Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Date:   Mon Apr 27 10:57:34 2015 -0400
> 
>     Fix: discover Debian API
>     
>     Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> 
> Enjoy :)

Great, thank you,

-- 
Jon