Re: [PATCH 1/5] cpumask: update irq_desc to use cpumask_var_t

[Mike Travis <travis@sgi.com>]

Yinghai Lu wrote:
> On Wed, Jan 7, 2009 at 11:58 AM, Mike Travis <travis@sgi.com> wrote:
> | --- linux-2.6-for-ingo.orig/kernel/irq/numa_migrate.c
> | +++ linux-2.6-for-ingo/kernel/irq/numa_migrate.c
> | @@ -46,6 +46,7 @@ static void init_copy_one_irq_desc(int i
> | 	desc->cpu = cpu;
> | 	lockdep_set_class(&desc->lock, &irq_desc_lock_class);
> | 	init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);
> |+	init_copy_desc_masks(old_desc, desc);
> | 	arch_init_copy_chip_data(old_desc, desc, cpu);
> | }
> |
> |@@ -76,11 +77,20 @@ static struct irq_desc *__real_move_irq_
> | 	node = cpu_to_node(cpu);
> | 	desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
> | 	if (!desc) {
> |-		printk(KERN_ERR "irq %d: can not get new irq_desc for migration.\n", irq);
> |+		printk(KERN_ERR "irq %d: can not get new irq_desc "
> |+				"for migration.\n", irq);
> | 		/* still use old one */
> | 		desc = old_desc;
> | 		goto out_unlock;
> | 	}
> |+	if (!init_alloc_desc_masks(desc, node, false)) {
> |+		printk(KERN_ERR "irq %d: can not get new irq_desc cpumask "
> |+				"for migration.\n", irq);
> |+		/* still use old one */
> |+		kfree(desc);
> |+		desc = old_desc;
> |+		goto out_unlock;
> |+	}
> | 	init_copy_one_irq_desc(irq, old_desc, desc, cpu);
> 
> desc new mask_var (allocated) aka the pointer is overwritten here...
> you may need to calling move init_alloc_desc_masks() into
> init_copy_one_irq_desc()

Wouldn't this in init_copy_one_irq_desc() take care  of that?

@@ -46,6 +46,7 @@ static void init_copy_one_irq_desc(int i
        desc->cpu = cpu;
        lockdep_set_class(&desc->lock, &irq_desc_lock_class);
        init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);
+       init_copy_desc_masks(old_desc, desc);
        arch_init_copy_chip_data(old_desc, desc, cpu);

where:

static inline void init_copy_desc_masks(struct irq_desc *old_desc,
                                        struct irq_desc *new_desc)
{
#ifdef CONFIG_CPUMASKS_OFFSTACK
        cpumask_copy(new_desc->affinity, old_desc->affinity);

#ifdef CONFIG_GENERIC_PENDING_IRQ
        cpumask_copy(new_desc->pending_mask, old_desc->pending_mask);
#endif
#endif
}

In other words if the masks are not a cpumask[1] but instead a
*cpumask pointer, then the old masks are copied to the new desc/

Or am I missing your point?

Thanks!
Mike

> 
> | 	irq_desc_ptrs[irq] = desc;
> 
> YH
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