Subject: Re: linux-next: Tree for July 18: warning at kernel/lockdep.c:2068 trace_hardirqs_on_caller

From: "Vegard Nossum" <[email-masked]>
Date: Sat, 19 Jul 2008 14:59:12 +0200

On Sat, Jul 19, 2008 at 11:55 AM, Vegard Nossum <[email-masked]> wrote:
> What I don't get here is how SLUB can be used this early in the boot
> process. Notice that this is still miles away from the
>
>    SLUB: Genslabs=12, HWalign=128, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
>
> line, which comes much later. And that kobject_init() _is_ calling
> kzalloc() via verify_dynamic_kobject_allocation(). Isn't this an
> error?
>
> (Unfortunately, my "git log" doesn't turn up any recent changes for
> any of the affected code paths here.)

Ehe... and this is the reason why: The code was added by this patch:

commit 0e3638d1e04040121af00195f7e4628078246489
Author: Dave Hansen <[email-masked]>
Date:   Thu Mar 16 17:30:16 2006 -0800

    warn when statically-allocated kobjects are used

..which only exists in -next. Is that just a truly ancient patch, or
did somebody forget to adjust their clock?

(Stephen: Maybe this has been answered before, but what's the best way
to figure out where it came from?)

Vegard

-- 
"The animistic metaphor of the bug that maliciously sneaked in while
the programmer was not looking is intellectually dishonest as it
disguises that the error is the programmer's own creation."
	-- E. W. Dijkstra, EWD1036