On Sun, 8 Jul 2012, Fengguang Wu wrote:

> Hi Vegard,
>
> This warning code is triggered for the attached config:
>
> __lockdep_trace_alloc():
>         /*
>          * Oi! Can't be having __GFP_FS allocations with IRQs disabled.
>          */
>         if (DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)))
>                 return;
>
> Where the irq is possibly disabled at the beginning of __slab_alloc():

Rights its possible. Depends on the callers specification of gfp flags.