Re: [PATCH 1/6] of: Do not free memory at of_node_release

[Guenter Roeck <linux@roeck-us.net>]

On 06/24/2014 07:10 AM, Grant Likely wrote:
> On Sun, 22 Jun 2014 12:40:34 +0300, Pantelis Antoniou <pantelis.antoniou@konsulko.com> wrote:
>> The life-cycle of nodes and properties does not allow us to release
>> the memory taken by a device_node. Pointer to properties and nodes
>> might still be in use in drivers, so any memory free'ing is dangerous.
>>
>> Simply move all the properties to the deadprops list, and the node
>> itself to of_alldeadnodes until the life-cycles issues are resolved.
>
> Ummm. this looks wrong. The release function is supposed to be the place
> to do the freeing, and with our discussion the other day about moving to
> rcu, but keeping of_node_get/put() for anything that needs to hold a
> long term reference, that means the lifecycle issues are pretty much
> resolved. I don't think this patch is necessary.
>
I am also a bit concerned about its implications. Does it mean that repeated
insertion/removal of an overlay will result in memory leaks ? I am sure
we'll find a bunch of memory leaks over time, but this looks like an
intentional one, which could be easy to create trouble if a system is
supposed to stay up for months or years.

Thanks,
Guenter