svn commit: r210586 - projects/ofed/head/sys/ofed/include/linux

[Jeff Roberson]

On Wed, 28 Jul 2010, Alan Cox wrote:

> Jeff Roberson wrote:
>> Author: jeff
>> Date: Thu Jul 29 02:12:22 2010
>> New Revision: 210586
>> URL: http://svn.freebsd.org/changeset/base/210586
>> 
>> Log:
>>    - Refine various page allocation methods.  They all essentially override
>>      the page object pointer to cache the virtual address after allocation.
>>      This same trick is used in UMA to store the slab address and so it
>>      should be safe.
>> 
>
> You needn't do this.  The virtual address of a kernel_object or kmem_object 
> page is easily obtained:
>
>   VM_MIN_KERNEL_ADDRESS + IDX_TO_OFF(m->pindex)

Ah, of course.  I hadn't considered that.  Thanks.  I'll remove the other 
hackery.

On another note; linux guarantees multipage allocations are aligned on the 
first power of two size that satisfies the allocation.  I can do this with 
contigmalloc but they also guarantee that the virtual address is similarly 
aligned.  I don't think I've run across anything that requires it, but if 
I do, do we have any provision for allocating virtually aligned addresses?

Thanks,
Jeff

>
>
> Regards,
> Alan
>