Re: [PATCH 3/4] zsmalloc use zs_handle instead of void *

[Seth Jennings <sjenning@linux.vnet.ibm.com>]

On 05/10/2012 09:47 AM, Nitin Gupta wrote:

> On 5/10/12 10:02 AM, Konrad Rzeszutek Wilk wrote:
>> struct zs {
>>     void *ptr;
>> };
>>
>> And pass that structure around?
>>
> 
> A minor problem is that we store this handle value in a radix tree node.
> If we wrap it as a struct, then we will not be able to store it directly
> in the node -- the node will have to point to a 'struct zs'. This will
> unnecessarily waste sizeof(void *) for every object stored.


I don't think so. You can use the fact that for a struct zs var, &var
and &var->ptr are the same.

For the structure above:

void * zs_to_void(struct zs *p) { return p->ptr; }
struct zs * void_to_zs(void *p) { return (struct zs *)p; }

Right?

--
Seth

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>