On Wed, Oct 28, 2020 at 08:03:37PM -0000, GitLab Bridge on behalf of dzickusrh wrote: > From: Don Zickus <[email protected]> > > There are two parts to this fix. One is using the recommended way > to disable LTO. The other is to make it work for the kernel.spec > file. > > Various kernel-tool programs (like perf) can not handle LTO yet, so > they are disabled. > > This is done with '%define _lto_cflags {nil}'. > > However that doesn't quite work for the kernel for the %install > section. It works for the %build section. > > Oddly, back at the birth of dist-git, the initial kernel.spec > file was imported with a line at the top > > %global __spec_install_pre %{___build_pre} > > For whatever reason, the kernel was deemed special and that line > pre-built the %install scripts _before_ the lto_cflags could > dynamically be disabled. > > Moving the _lto_cflags line above the _pre line disables LTO for both the > %build and %install sections of the spec file successfully. > > However, because that _pre line is unintiutive and caused hours > of debugging headache, I hacked up the output to see what the > %__spec_install_pre and ___build_pre looked like at the > beginning of the %install section. The idea was __build_pre > is what we want going forward. > > Unfortunately, after examining the results, I learned the %install > section expects a clean RPM_BUILD_ROOT. But the kernel %build > section puts each compiled variant into the RPM_BUILD_ROOT as > it completes. Thus is gets removed on %install setup. So the > %__spec_install_pre line has to stay. > > Instead I add a bunch of comments explaining why it is necessary > and where to add changes like _lto_cflags. This hopefully > reduces headaches in the future. > > V2: restore __spec_install_pre line and add comments. > > Cc: Jeff Law <[email protected]> > Signed-off-by: Don Zickus <[email protected]>
I like this version much better. Acked-by: Brian Masney <[email protected]> _______________________________________________ kernel mailing list -- [email protected] To unsubscribe send an email to [email protected] Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/[email protected]
