Re: [PATCH v2] lttng-modules: Backport patches to fix compilation failures since kernel v5.1

[Adrian Bunk <bunk@stusta.de>]

On Tue, Jun 11, 2019 at 11:49:34PM +0100, Richard Purdie wrote:
> On Tue, 2019-06-11 at 17:03 +0800, zhe.he@windriver.com wrote:
> > From: He Zhe <zhe.he@windriver.com>
> > 
> > For the moment,
> > 0001~0004 are on master branch only.
> > 0005~0007 are on stable-2.11 branch, but v2.11 has not been released
> > yet.
> > 
> > Signed-off-by: He Zhe <zhe.he@windriver.com>
> > ---
> > v2: Correct a typo in SOB for 0001*.patch
> 
> I just discussed this with lttng upstream maintainers a little. We're
> going to have continual tension between keeping lttng-modules up to
> date and new kernel versions.
> 
> How about we also have a git version of this particular recipe which
> has a DEFAULT_PREFERENCE = "-1" but people can opt into with a
> PREFERRED_VERSION when using newer kernels?

Yocto stable series will ship a _git AUTOREV recipe?

> That should keep people using very recent kernels happy, let us use a
> stable release version and avoid us adding/removing large patchsets on
> a semi regular basis?
>...

The semi regular basis is only slightly moved, or how and when will 
replacing the already EOL kernel 5.0 with 5.1 in Yocto be handled?

IMHO it would be better to acknowledge that this is a case where staying 
at stable release versions is sometimes not the best option, and upgrade 
the normal recipe to -rc releases or even a git snapshot from a more 
recent stable branch when necessary.

E.g. right now it seems clear that the next Yocto release will have
to use lttng-modules >= 2.11 in any case for kernel 5.2, so upgrading
from 2.10.9 to 2.11.0-rc5 would be logical.

> Cheers,
> 
> Richard

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed