Re: [Bug #13319] Page allocation failures with b43 and p54usb

David Rientjes
2009-06-30T20:26:18Z

On Tue, 30 Jun 2009, Pekka Enberg wrote:

> On Tue, Jun 30, 2009 at 10:47 AM, David Rientjes<rientjes@google.com> wrote:
> > I don't think CONFIG_SLUB_DEBUG_ON is generally the configuration used in
> > the real world.
>
> It is, hence the epic bug report that's eaten too many man hours
> already! Look, we encourage _testers_ to turn all as much as debugging
> options as possible so we catch bugs early. That why the only sane
> defaults are the ones that don't cause other problems!
>

I feel that asking a user to add a command line parameter such as
`slub_debug=A' in addition to CONFIG_SLUB_DEBUG_ON will likely lead to
less testing coverage and bugs going unreported. CONFIG_SLUB_DEBUG_ON is
not something that a distro is going to enable or would be used in a
production environment, it's something that's used to debug slub and/or
slab allocations either during the development of new kernel code or when
an underlying problem is realized.

> I don't know why you want to argue this. It's simply not an option to
> say "stupid user, fix your config" in core code like the slab
> allocator. Enabling CONFIG_SLUB_DEBUG_ON is a very reasonable thing to
> do when you are a tester looking for bugs.
>

Quite the contrary, I agree completely with the above, and that's why I'm
arguing for full debugging to be enabled when a well-defined configuration
option is enabled. I simply don't believe that such debugging should be
coupled with a command line option to be fully activated for all caches.