Re: A question about compiling Linux kernel

From: Bagas Sanjaya
Date: Thu Mar 09 2023 - 21:21:59 EST


On 3/10/23 04:22, Mirsad Goran Todorovac wrote:
> Hi Mr. Bagas,
>
> If you can recall, you instructed me to use ccache, however with frequent rebuilds
> and especially bisects it would be better to recompile just the objects that have
> changed between the versions, rather than doing "make clean; make CC='ccache gcc'"
>
> Is it safe to just do make CC='ccache gcc' and let make decide what to recompile?
>

I have tried building a userspace application, for which the source code is
obtained by git. I do the initial build first, then git pull-ing without cleaning
the build directory, then incremental rebuild (usually `make` or `ninja`).
The incremental build only rebuild what is changed. However, when the version
identifier (mostly via build config) is changed, all previous build artifacts
are invalidated, essentially rebuild from scratch.

IMO, above can also be applied to Linux kernel (but I haven't tried to build
that way).

Cc: linux-kbuild list since I'm unsure on this.

Thanks.

--
An old man doll... just what I always wanted! - Clara