Oliver O'Halloran <ooh...@gmail.com> writes: > On Wed, Apr 19, 2017 at 2:46 AM, Rob Herring <robh...@kernel.org> wrote: >> On Mon, Apr 17, 2017 at 7:32 PM, Tyrel Datwyler >> <tyr...@linux.vnet.ibm.com> wrote: >>> This patch introduces event tracepoints for tracking a device_nodes >>> reference cycle as well as reconfig notifications generated in response >>> to node/property manipulations. >>> >>> With the recent upstreaming of the refcount API several device_node >>> underflows and leaks have come to my attention in the pseries (DLPAR) >>> dynamic >>> logical partitioning code (ie. POWER speak for hotplugging virtual and >>> physcial >>> resources at runtime such as cpus or IOAs). These tracepoints provide a >>> easy and quick mechanism for validating the reference counting of >>> device_nodes during their lifetime. >> >> Not really relevant for this patch, but since you are looking at >> pseries and refcounting, the refcounting largely exists for pseries. >> It's also hard to get right as this type of fix is fairly common. It's >> now used for overlays, but we really probably only need to refcount >> the overlays or changesets as a whole, not at a node level. If you >> have any thoughts on how a different model of refcounting could work >> for pseries, I'd like to discuss it. > > One idea I've been kicking around is differentiating short and long > term references to a node.
I actually did this a long time ago, but balked at the size of the patch to do the conversion. Let me see if I can find it lying around ... cheers
