Re: possible debug config extension
On Sun, May 29, 2016 at 9:56 AM, Jiri Pirko <jiri(a)resnulli.us> wrote:
Hi.
There could be really handy to have more debug options enabled in debug
kernel. Namely:
CONFIG_PREEMPT=y
That's not a debug option.
CONFIG_DEBUG_PREEMPT=y
CONFIG_SLUB_DEBUG=y
This is already enabled.
CONFIG_SLUB_DEBUG_ON=y
We don't enable this because it makes graphics performance such that
people don't even want to use rawhide.
CONFIG_DEBUG_PAGEALLOC=y
CONFIG_KASAN=y
Very large performance hits.
CONFIG_PANIC_ON_OOPS=y
This would render a lot of machines unusable for little reason.
CONFIG_UBSAN=y
CONFIG_UBSAN_SANITIZE_ALL=y
KASan is especially useful.
However the overhead of KASan for example is quite significant. So the
question is, would it make sense to add these to the debug config?
IMO, no.
Another option would be to introduce a "deeper-debug"
config and do an
extra rpm for that. That would let user to choose between ordinary debug
kernel and deeper debug kernel.
What do you think?
That sounds like a lot of burden to maintain. Every flavor or
subpackage we introduce makes the kernel.spec even more unreadable.
It might be better suited as a COPR, particularly since the given user
base is going to be relatively small.
josh