Comment # 3 on bug 1200487 from Jiri Slaby

(In reply to Mel Gorman from comment #2)
> (In reply to Jiri Slaby from comment #1)
> > Just a note: it's still pretty fragile. So if it crashes, just please let me
> > know your setup and the crash. I'll try to fix it up.
> 
> Are there any toolchain support changes or is SLE 15 SP4 userspace suitable?

I am not sure if you mean for building or running.

Building:
lto is supported for a long time in gcc, so gcc-7 (and the rest of the 15sp4's
toolchain) should be fine. But noone tried, so I would expect glitches.

Running:
It won't run there as it is currently built (i.e. against Tumbleweed). But it's
quite easy to fix the IBS projects to build against backports, so that it runs
on 15sp4 just fine.

> Are there kernel.org branches should LTO enabled vs disabled?

Sorry, I don't understand what you are asking here. Do you want me to push an
upstream kernel w/ and w/o LTO patches to git.kernel.org?

> Factory as userspace would be problematic as it keeps changing and has
> limited to no remote deployment support currently available. I also need to
> have an idea of what patches are applied just to make LTO an option because
> the real comparison should not be between LTO enabled vs disabled but
> between vanilla mainline vs LTO-disabled vs LTO-enabled. Given that it is
> expected to be fragile and likely break, it'll be only queued against one
> machine as a starting point.

OK, the project setup allows for an easy diff -- it's linked against
Kernel:stable. So the patches (and a config diff) are these:
https://build.suse.de/package/rdiff/home:jirislaby:kernel-lto/kernel-source?opackage=kernel-source&oproject=Devel%3AKernel%3Astable

Or you can download patches.addon.tar.bz2 from home:jirislaby:kernel-lto
directly:
https://build.suse.de/source/home:jirislaby:kernel-lto/kernel-source/patches.addon.tar.bz2

And the config changes too:
https://build.suse.de/source/home:jirislaby:kernel-lto/kernel-source/config.addon.tar.bz2