Re: starting with 2.7

From: David Lang
Date: Tue Jan 04 2005 - 15:40:22 EST

Sorry, I've been useing kernel.org kernels since the 2.0 days and even within a stable series I always do a full set of tests before upgrading. every single stable series has had 'paper bag' releases, and every single one has had fixes to drivers that have ended up breaking those drivers.

the only way to know if a new kernel will work on your hardware is to try it. It doesn't matter if the upgrade is from 2.4.24 to 2.4.25 or 2.6.9 to 2.6.10 or even 2.4.24 to 2.6.10

anyone who assumes that just becouse the kernel is in the stable series they can blindly upgrade their production systems is just dreaming.

David Lang

On Tue, 4 Jan 2005, Adrian Bunk wrote:

Date: Tue, 4 Jan 2005 18:47:13 +0100
From: Adrian Bunk <bunk@xxxxxxxxx>
To: Arjan van de Ven <arjan@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>, Andries Brouwer <aebr@xxxxxxxxxx>,
William Lee Irwin III <wli@xxxxxxxxxxxxxx>,
Maciej Soltysiak <solt2@xxxxxxxxxxxxxxxxx>, linux-kernel@xxxxxxxxxxxxxxx
Subject: Re: starting with 2.7

On Mon, Jan 03, 2005 at 04:59:02PM +0100, Arjan van de Ven wrote:
On Mon, 2005-01-03 at 16:34 +0100, Adrian Bunk wrote:
On Mon, Jan 03, 2005 at 10:18:47AM -0500, Rik van Riel wrote:
On Sun, 2 Jan 2005, Andries Brouwer wrote:

You change some stuff. The bad mistakes are discovered very soon.
Some subtler things or some things that occur only in special
configurations or under special conditions or just with
very low probability may not be noticed until much later.

Some of these subtle bugs are only discovered a year
after the distribution with some particular kernel has
been deployed - at which point the kernel has moved on
so far that the fix the distro does might no longer
apply (even in concept) to the upstream kernel...

This is especially true when you are talking about really
big database servers and bugs that take weeks or months
to trigger.

If at this time 2.8 was already released, the 2.8 kernel available at
this time will be roughly what 2.6 would have been under the current
development model, and 2.6 will be a rock stable kernel.

as long as more things get fixed than new bugs introduced (and that
still seems to be the case) things only improve in 2.6.
...

My main point is not the number of bugs, but the number of regressions.

If you do install a new machine or do a major upgrade (e.g. 2.4 -> 2.6)
you do some testing whether everything works as expected and if
something doesn't work, you try to get it working or work around the
problem.

Inside a stable kernel series (e.g. 2.6.x -> 2.6.y) you hope that an
upgrade doesn't contain regressions and goes smoothly.

Even the introduction of CONFIG_BLK_DEV_UB in 2.6.9 [1] has bitten
several people I know.

cu
Adrian

[1] this is not technically a bug, but e.g. similar common problems
for users in the input code were already fixed during 2.5 long
before 2.6.0

--

"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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