Re: [PATCH 03/25] add dyn_array support

[Johannes Weiner]

Hi,

"Yinghai Lu" <yhlu.kernel@xxxxxxxxx> writes:

> On Sat, Aug 2, 2008 at 10:31 PM, Johannes Weiner <hannes@xxxxxxxxxxxx> wrote:
>> Hi,
>>
>> "Yinghai Lu" <yhlu.kernel@xxxxxxxxx> writes:
>>
>>> On Sat, Aug 2, 2008 at 9:55 PM, Johannes Weiner <hannes@xxxxxxxxxxxx> wrote:
>>>> Hi,
>>>>
>>>> "Yinghai Lu" <yhlu.kernel@xxxxxxxxx> writes:
>>>>
>>>>> On Sat, Aug 2, 2008 at 9:03 PM, Johannes Weiner <hannes@xxxxxxxxxxxx> wrote:
>>>>>> Hi,
>>>>>>
>>>>>> Yinghai Lu <yhlu.kernel@xxxxxxxxx> writes:
>>>>>>
>>>>>>> could have crazy big arrays and allocate them in bootmem at init stage.
>>>>>>> also also to allocate array according to size we need to use to avoid wasting
>>>>>>> memory
>>>>>>> use CONFIG_HAVE_DYN_ARRAY to enable it or not
>>>>>>>
>>>>>>> usage:
>>>>>>>
>>>>>>> |static struct irq_desc irq_desc_init __initdata = {
>>>>>>> |       .status = IRQ_DISABLED,
>>>>>>> |       .chip = &no_irq_chip,
>>>>>>> |       .handle_irq = handle_bad_irq,
>>>>>>> |       .depth = 1,
>>>>>>> |       .lock = __SPIN_LOCK_UNLOCKED(irq_desc->lock),
>>>>>>> |#ifdef CONFIG_SMP
>>>>>>> |       .affinity = CPU_MASK_ALL
>>>>>>> |#endif
>>>>>>> |};
>>>>>>> |
>>>>>>> |static void __init init_work(void *data)
>>>>>>> |{
>>>>>>> |       struct dyn_array *da = data;
>>>>>>> |       struct  irq_desc *desc;
>>>>>>> |       int i;
>>>>>>> |
>>>>>>> |       desc = *da->name;
>>>>>>
>>>>>> Where *da->name might be NULL...
>>>
>>> *da->name = __alloc_bootmem_nopanic(size, da->align, phys);
>>
>> Exactly.  Now, look up the possible return values of
>> __alloc_bootmem_nopanic and we are almost there...
>
> 04 fix that via allocating that all together

No patch should introduce wrong behaviour but instead be an atomic
switch to another working state.  If 4 gets reverted for any reason
whatsoever, you will be left with a buggy version.

	Hannes
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/