svn commit: r204808 - head/sys/net

[Bjoern A. Zeeb]

On Sun, 7 Mar 2010, Bruce Cran wrote:

> On Sat, Mar 06, 2010 at 09:27:26PM +0000, Bjoern A. Zeeb wrote:
>> Author: bz
>> Date: Sat Mar  6 21:27:26 2010
>> New Revision: 204808
>> URL: http://svn.freebsd.org/changeset/base/204808
>>
>> Log:
>>   Introduce a function rn_detachhead() that will free the
>>   radix table root nodes.  This is only needed (and available)
>>   in the virtualization case to free the resources when tearing
>>   down a virtual network stack.
>>
>>   Sponsored by:	ISPsystem
>>   Reviewed by:	julian, zec
>>   MFC after:	5 days
>>
>> Modified:
>>   head/sys/net/radix.c
>>   head/sys/net/radix.h
>>
>> Modified: head/sys/net/radix.c
>> ==============================================================================
>> --- head/sys/net/radix.c	Sat Mar  6 21:24:32 2010	(r204807)
>> +++ head/sys/net/radix.c	Sat Mar  6 21:27:26 2010	(r204808)
>> @@ -1161,6 +1161,24 @@ rn_inithead(head, off)
>>  	return (1);
>>  }
>>
>> +#ifdef VIMAGE
>> +int
>> +rn_detachhead(void **head)
>> +{
>> +	struct radix_node_head *rnh;
>> +
>> +	KASSERT((head != NULL && *head != NULL),
>> +	    ("%s: head already freed", __func__));
>> +	rnh = *head;
>> +
>> +	/* Free <left,root,right> nodes. */
>> +	Free(rnh);
>> +
>> +	*head = NULL;
>> +	return (1);
>> +}
>> +#endif
>
> Is this sufficient to free all the memory? From what I can see, 'Free' is
> just freeing the pointer and not walking the tree to free the nodes too.
>
> I don't know if the memory allocation is being done differently, but I
> fixed the same issue on Windows by introducing a 'rn_free_subtree'
> function - I don't know if it's entirely correct but the code can be
> seen at http://www.bluestop.org/viewvc/repos/sctpDrv/net/radix.c?r1=24&r2=23&pathrev=24
>
> I also found that rn_zeros wasn't being freed when the driver got
> unloaded.

You will notice that it's not called from anywhere yet;)

I have another dozen of patches to fix various places and free things.
Freeing of the tree is (will be) done from route.c (from my memory).

I am just flushing the "easy" ones from my patch queue while slowly
reaching timeout for the others that I had sent out for review.
In case you want to have a look at the complete set send me a mail to
bz@ and I'll forward you the remaining set.

/bz

-- 
Bjoern A. Zeeb         It will not break if you know what you are doing.