From: Theodore Ts'o <tytso@mit.edu>
To: Olof Johansson <olof@lixom.net>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>,
"ltsi-dev@lists.linuxfoundation.org"
<ltsi-dev@lists.linuxfoundation.org>,
"ksummit-discuss@lists.linuxfoundation.org"
<ksummit-discuss@lists.linuxfoundation.org>,
"gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Subject: Re: [Ksummit-discuss] [Stable kernel] feature backporting collaboration
Date: Sat, 3 Sep 2016 20:10:31 -0400 [thread overview]
Message-ID: <20160904001031.t7sv5isw5tc46pxr@thunk.org> (raw)
In-Reply-To: <CAOesGMibzGC3Nz+DmERJUea4jbJQ28hDGDGMuHkr+o=Wb3iUdA@mail.gmail.com>
On Fri, Sep 02, 2016 at 11:21:38AM -0700, Olof Johansson wrote:
>
> The one case where it is warranted is for features that went in since
> the last LTS release.
>
> Pushing vendors all the way to target a non-LTS release is a bit more
> aggressive that needed, in my opinion.
So maybe they shouldn't target 4.7 before 4.8 has been released, but
once 4.8 is released, what's the problem with having vendors use 4.7.x
at that point (where x would probably be 2 or 3)?
We've already established that they don't track the stable kernel bug
fixes, but are instead cherry picking fixes. So let's suppose 4.9
turns out to be next LTS kernel. The only downside of using 4.7.x for
an SOC kernel is people will have to search the 4.7.x, 4.8.x, and
4.9.x stable kernels to find commits to cherry pick. Is that really
that much harder?
The big problem is knowing that there are patches to cherry pick, and
hoping that all of the mobile handset vendors know to cherry pick all
of the patches for their diverged, forked kernel. Is needing to
search multiple stable kernels really a sigificant part of the cost of
updating the device kernel?
At this point, the only thing thing the LTS seems to provide is that
it limits the number of kernels that patches needed to backported to,
and it limits the number of sets of stable kernel patches that device
vendor maintainers need to search to find patches to backport from.
If it reduces the number of massive features that have to be
backported to 4.4, it might be that pushing them to use 4.7 (or
waiting for the next LTS kernel, which should hopefully be coming soon
anyway) might be less risky and less work than trying to back port
feature patchsets to 4.4 or 3.18.
- Ted
next prev parent reply other threads:[~2016-09-04 0:10 UTC|newest]
Thread overview: 122+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-01 2:01 Alex Shi
2016-09-02 1:25 ` Levin, Alexander
2016-09-02 2:43 ` Stephen Hemminger
2016-09-02 9:59 ` Mark Brown
2016-09-02 9:54 ` Mark Brown
2016-09-02 10:16 ` [Ksummit-discuss] [LTSI-dev] " Geert Uytterhoeven
2016-09-02 14:42 ` [Ksummit-discuss] " James Bottomley
2016-09-02 14:55 ` Rik van Riel
2016-09-02 15:04 ` James Bottomley
2016-09-02 15:39 ` Rik van Riel
2016-09-02 17:06 ` Bird, Timothy
2016-09-05 1:45 ` NeilBrown
2016-09-05 11:04 ` Mark Brown
2016-09-05 22:44 ` NeilBrown
2016-09-06 0:57 ` Mark Brown
2016-09-06 5:41 ` NeilBrown
2016-09-08 18:33 ` [Ksummit-discuss] [LTSI-dev] " Bird, Timothy
2016-09-08 22:38 ` NeilBrown
2016-09-09 11:01 ` Mark Brown
2016-09-09 22:17 ` NeilBrown
2016-09-12 17:37 ` Mark Brown
2016-09-13 7:46 ` NeilBrown
2016-09-13 17:53 ` Mark Brown
2016-09-02 18:21 ` [Ksummit-discuss] " Olof Johansson
2016-09-02 23:35 ` Mark Brown
2016-09-03 5:29 ` Guenter Roeck
2016-09-03 10:40 ` Mark Brown
2016-09-04 0:10 ` Theodore Ts'o [this message]
2016-09-04 8:34 ` gregkh
2016-09-04 22:58 ` Amit Kucheria
2016-09-04 23:51 ` Theodore Ts'o
2016-09-05 12:58 ` Mark Brown
2016-09-05 11:11 ` Mark Brown
2016-09-05 14:03 ` Theodore Ts'o
2016-09-05 14:22 ` Laurent Pinchart
2016-09-06 0:35 ` Mark Brown
2016-09-06 15:30 ` James Bottomley
2016-09-06 19:44 ` gregkh
2016-09-06 22:20 ` Mark Brown
2016-09-06 22:34 ` James Bottomley
2016-09-08 18:55 ` Bird, Timothy
2016-09-08 19:19 ` gregkh
2016-09-09 10:45 ` Mark Brown
2016-09-09 11:03 ` gregkh
2016-09-09 11:48 ` Mark Brown
2016-09-06 23:23 ` Mark Brown
2016-09-06 13:34 ` Catalin Marinas
2016-09-06 16:24 ` Bartlomiej Zolnierkiewicz
2016-09-06 16:25 ` Guenter Roeck
2016-09-06 22:39 ` Mark Brown
2016-09-07 8:33 ` Jan Kara
2016-09-07 8:41 ` Jiri Kosina
2016-09-07 18:44 ` Mark Brown
2016-09-08 17:06 ` Frank Rowand
2016-09-09 10:32 ` Mark Brown
2016-09-09 15:21 ` Alex Shi
2016-09-12 15:34 ` Christoph Hellwig
2016-09-06 16:46 ` Olof Johansson
2016-09-08 8:34 ` Linus Walleij
2016-09-08 8:55 ` Vinod Koul
2016-09-09 14:32 ` Rob Herring
2016-09-09 14:23 ` Rob Herring
[not found] ` <2181684.5VzIQ6DWv4@amdc1976>
2016-09-07 9:32 ` Catalin Marinas
2016-09-07 13:07 ` Bartlomiej Zolnierkiewicz
2016-09-07 18:49 ` Mark Brown
2016-09-09 15:06 ` Alex Shi
2016-09-02 23:29 ` Mark Brown
2016-09-02 19:16 ` Levin, Alexander
2016-09-03 0:05 ` Mark Brown
2016-09-05 9:28 ` Laurent Pinchart
2016-09-21 6:58 ` Alex Shi
2016-09-21 9:23 ` gregkh
2016-09-21 14:52 ` Alex Shi
2016-09-21 15:28 ` gregkh
2016-09-21 18:50 ` Mark Brown
2016-09-22 3:15 ` Alex Shi
2016-09-21 18:22 ` Mark Brown
2016-09-21 18:54 ` Linus Walleij
2016-09-21 19:52 ` Theodore Ts'o
2016-09-22 0:43 ` Mark Brown
2016-09-22 5:20 ` gregkh
2016-09-22 12:56 ` Laurent Pinchart
2016-09-22 16:22 ` Mark Brown
2016-09-22 22:14 ` Theodore Ts'o
2016-09-23 12:28 ` Laurent Pinchart
2016-09-23 13:27 ` [Ksummit-discuss] [LTSI-dev] " Alex Shi
2016-09-23 13:40 ` Laurent Pinchart
2016-09-23 14:40 ` [Ksummit-discuss] " Mark Brown
2016-09-21 13:56 ` Theodore Ts'o
2016-09-21 15:23 ` Alex Shi
2016-09-21 15:33 ` gregkh
2016-09-21 19:16 ` Mark Brown
2016-09-02 13:47 ` Theodore Ts'o
2016-09-02 19:31 ` Levin, Alexander
2016-09-02 19:42 ` gregkh
2016-09-02 20:06 ` Levin, Alexander
2016-09-03 2:04 ` Mark Brown
2016-09-06 7:20 ` [Ksummit-discuss] [LTSI-dev] " Tsugikazu Shibata
2016-09-10 12:00 ` Theodore Ts'o
2016-09-12 16:27 ` Mark Brown
2016-09-12 17:14 ` Greg KH
2016-09-12 23:45 ` Mark Brown
2016-09-13 3:14 ` Theodore Ts'o
2016-09-13 10:14 ` Mark Brown
2016-09-13 13:19 ` Levin, Alexander
2016-09-13 6:19 ` Greg KH
2016-09-13 10:38 ` Mark Brown
2016-09-13 12:09 ` Greg KH
2016-09-13 12:20 ` Josh Boyer
2016-09-13 13:12 ` Greg KH
2016-09-13 16:23 ` Bird, Timothy
2016-09-13 19:02 ` Mark Brown
2016-09-14 14:47 ` Alex Shi
2016-09-20 5:15 ` Tsugikazu Shibata
2016-09-21 8:46 ` Alex Shi
2016-09-13 12:25 ` Geert Uytterhoeven
2016-09-13 19:21 ` Mark Brown
2016-09-14 1:49 ` Greg KH
2016-09-14 3:00 ` Guenter Roeck
2016-09-12 4:12 ` Alex Shi
2016-09-12 16:09 ` Masami Hiramatsu
2016-09-13 2:39 ` Alex Shi
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