On Wed, 22 Aug 2007, Mathieu Desnoyers wrote:
> * Christoph Lameter ([EMAIL PROTECTED]) wrote:
> > void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags)
> > @@ -1577,7 +1590,10 @@ static void __slab_free(struct kmem_cach
> > {
> > void *prior;
> > void **object = (void *)x;
> > + unsigned long flags;
> >
> > + local_irq_save(flags);
> > + put_cpu_no_resched();
>
> Those two lines may skip a preempt_check.
Yes we cannot execute something else here.
> Could we change them to this instead ?
>
> put_cpu();
> local_irq_save(flags);
Then the thread could be preempted and rescheduled on a different cpu
between put_cpu and local_irq_save() which means that we loose the
state information of the kmem_cache_cpu structure.
> Otherwise, it would be good to call
>
> preempt_check_resched();
>
> After each local_irq_restore() in this function.
We could do that but maybe the frequency of these checks would be too
high? When should the resched checks be used?
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