ACK/Cmnt: [SRU][Unstable/Q/P/N/J][PATCH 0/5] sources list generation using dwarfdump takes up to 0.5hr in build process (LP: #2104911)

[Stefan Bader]

On 11.08.25 14:35, Juerg Haefliger wrote:
> BugLink: https://bugs.launchpad.net/bugs/2104911
> 
> [ Impact ]
> 
> In debian/rules.d/2-binary-arch.mk, stamp-build-% targets, we have:
> ```
> # Collect the list of kernel source files used for this build. Need to do this
> early
> # before modules are stripped. Fail if the resulting file is empty.
> find $(build_dir) \( -name vmlinux -o -name \*.ko \) -exec dwarfdump -i {} \; |
> \
>          grep -E 'DW_AT_(call|decl)_file' | sed -n 's|.*\s/|/|p' | sort -u > \
>          $(build_dir)/sources.list
> test -s $(build_dir)/sources.list
> ```
> 
> The process is single threaded and may takes up to half an hour to complete:
> ```
> $ time ...
> 
> real 28m15.167s
> user 54m32.917s
> sys 4m32.531s
> ```
> 
> [ Fix ]
> 
> This takes way too long. Parallelization introduces new/different issues. Remove
> the logic to collect the list of kernel source files during the build. We have
> all the data in the debug packages and can extract it after the build.
> 
> This reverts the changes for bug 2086606.
> 
> [ Test Plan ]
> 
> Inspect the build logs and the content of the linux-buildinfo packages to verify
> the data is no longer collected.
> 
> [ Where Problems Could Occur ]
> 
> Potential build failures.
> 
I guess now that I made a comment I have to also make the first step in 
approval... Questing already did this and we can follow up with the 
other series. At least this way round it is not fatal even if a 
derivative forgets to drop the build-dep...

Acked-by: Stefan Bader <stefan.bader at canonical.com>
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