Bug#837588: hppa: Please disable CONFIG_FTRACE for hppa architecture

[Helge Deller <deller@gmx.de>]

Package: linux
Version: 4.7.2-1
Severity: important

We sadly will need to disable CONFIG_FTRACE for hppa architecture completely for now.

The problem is, that gcc creates lots of overhead when adding the code for the
mcount call (minimum 16 bytes per function, plus two relocation symbol entries)
which leads that the 64bit vmlinux kernel file for 4.7 becomes around 99MB, while
vmlinux for kernel 4.6 was just around 17MB. This size wouldn't be a real problem itself,
but sadly the default /boot partition is currently maximum 128 MB in size which
is not able to keep the vmlinux file plus the size for the initrd image (which is a lot
bigger than 100MB then).
That leads to the fact, that people who have a default hppa installation will not
be able to install the new kernel (and don't have space in /boot to keep other older
images either).

So, can you please deactivate CONFIG_FTRACE completely for 32- and 64bit hppa configs?
Is it sufficient to add "CONFIG_FTRACE=n" to debian/config/hppa/config ?

Thanks!
Helge

PS: I'm still working on upstream ftrace support for hppa. It's not complete yet, so
we don't loose to much when we disable ftrace again now. Further more I will adjust the
debian installer to create bigger /boot partitions so that we can enable it later again.