Re: [PATCH -mm 3/6] slub: introduce __kfree_rcu

[Lai Jiangshan <laijs@cn.fujitsu.com>]

Christoph Lameter wrote:
> On Tue, 3 Mar 2009, Lai Jiangshan wrote:
> 
>> +
>> +void __kfree_rcu(const void *x, struct rcu_head *rcu)
>> +{
>> +	call_rcu(rcu, kfree_rcu_callback);
>> +}
>> +EXPORT_SYMBOL(__kfree_rcu);
>> +
> 
> The parameter x is unused why require it? I see that SLOB needs it. Cant
> you do a similar trick as in SLUB just calculating the start address of
> the object from the rcu address?
> 


The first parameter of __kfree_rcu() is unused in slab,slub,slqb.
(I used it before, for CONFIG_SLUB_DEBUG=y ...etc. But I found
these debugging code is needless)

Object sizes of the memory objects in slob's kmalloc-slab are various.
We hardly calculate the start address of the object from the rcu address.

Lai