Re: [PATCH -mm] slub: update cpu after new_slab()

From: Christoph Lameter
Date: Wed Apr 25 2007 - 11:29:47 EST

On Wed, 25 Apr 2007, Hugh Dickins wrote:

> SLUB gave me a NULL pointer dereference in slab_alloc(), in the
> slab_lock(page) of its "Current cpuslab is acceptable" block: cpu
> 1 had been looking at cpu_slab[2], which then went NULL beneath it.
> Since new_slab() may reenable interrupts and sleep (when __GFP_WAIT),
> we may get rescheduled on a different cpu: so need to reevaluate it.

Right. local_irq_save does not switch off preemption as I thought.

Acked-by: Christoph Lameter <clameter@xxxxxxx>
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