Re: Make 4.3 rebuilds .o files when unnecessary

[Tommaso Fonda]

The kernel tree I'm working on is much, much older than yours (it's Linux
3.4!)...
Given it's not a make-related problem, I guess it's a problem with Linux
3.4's general Makefile & build system. I'll have to stick to make 4.2,
however I'll try to build newer kernel trees (for x86_64, but it shouldn't
make any difference) to find which is the oldest in which I cannot
reproduce this issue. If I find the root cause of the problem, I might be
able to "backport" the fix from said kernel version into my 3.4 tree.
If you have any additional suggestions, do let me know, please!
Thank you to both of you for your help.
Regards,
--
Tommaso

Il giorno gio 19 nov 2020 alle ore 02:40 Kaz Kylheku (gmake) <
729-670-0061@kylheku.com> ha scritto:

> On 2020-11-18 16:10, Kaz Kylheku (gmake) wrote:
> > I regularly build the kernel as part of my work; I will build GNU Make
> > 4.3 from sources and see if this reproduces.
>
> I gave this a quick try; I built 4.3 under Ubuntu 18.04, from the
> release
> tarball, and mapped it into the Docker container where I'm doing
> builds of a kernel 4.9 for an ARM target. In my container, make 4.3 is
> known as /local/bin/make. I added a /local/bin/make --version call to my
> script to check this. It reports 4.3.
>
> The problem does not reproduce, unfortunately.
>
> The steps /local/bin/make $defconfig_file ; /local/bin/make uImage do
> the same incremental build as they do with 4.1.
>
> Oops!
>
> The kernel tree I'm working with (4.9) is fairly old, though,
> and probably different from yours.
>
> If this is caused by something in the build system, it could easily
> be sensitive to the kernel version.
>
>
>