Re: [PATCH 03/25] add dyn_array support

[Yinghai Lu]

On Sat, Aug 2, 2008 at 10:47 PM, Johannes Weiner <hannes@xxxxxxxxxxxx> wrote:
> 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.

ok, next version i will remove _nopanic

Yh
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