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

[He Zhe <zhe.he-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org>]

On 6/12/19 6:58 PM, Mathieu Desnoyers wrote:
> ----- On Jun 12, 2019, at 12:51 PM, Adrian Bunk bunk-HeJ8Db2Gnd6zQB+pC5nmwQ@public.gmane.org wrote:
>
>> On Tue, Jun 11, 2019 at 11:49:34PM +0100, Richard Purdie wrote:
>>> On Tue, 2019-06-11 at 17:03 +0800, zhe.he-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org wrote:
>>>> From: He Zhe <zhe.he-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org>
>>>>
>>>> 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-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org>
>>>> ---
>>>> 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.
> Please don't base distributions on -rc tags. They are not meant for this.
>
> We always integrate support for newer kernel versions instrumentation back
> into our current stable release. So as soon as 5.2 final comes out, we will
> release a 2.10.x version including support for it in lttng-modules.

I'm one of the people who need to use lttng-modules on rc kernel.

>
> The current 2.10.10 has commits to support the currently known 5.2-rc
> instrumentation changes.

Seems v2.10.10 does not contains the 7 needed patches in my v1 for kernel v5.0+.
$ git pull
Already up-to-date.
$ git tag|grep v2.10.10
v2.10.10
$ git tag --contains 92da05ce1f73488a57e7fd79e9c03113cefdb76f
$ git tag --contains d88e2fe5c3ea0d2c3055fba824be17223c418854
$ git tag --contains d6cd2c9598a06f0ba1ba885bbe754e8836528310
$ git tag --contains 2ca0c84f0b4a915c555a0b83102d94ac941619ca
$ git tag --contains da00122ccfae6a73ec859826a0be1cf0902cfd11
v2.11.0-rc5
$ git tag --contains da00122ccfae6a73ec859826a0be1cf0902cfd11
v2.11.0-rc5
$ git tag --contains df0e746a05a267384785d66c9fca947eb4a9e517
v2.11.0-rc5
$ git tag --contains 9f70b60c19abc6dc0811e427ed5da4aa74620aca
v2.11.0-rc5

Thanks,
Zhe

>
> Thanks,
>
> Mathieu
>
>
>>> 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

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