On Wed, Sep 3, 2025 at 8:38 AM Thierry Reding <thierry.red...@gmail.com> wrote: > > On Tue, Sep 02, 2025 at 03:37:45PM -0700, John Stultz wrote: > > On Tue, Sep 2, 2025 at 8:46 AM Thierry Reding <thierry.red...@gmail.com> > > wrote: > > > > > > From: Thierry Reding <tred...@nvidia.com> > > > > > > Add a callback to struct dma_heap_ops that heap providers can implement > > > to show information about the state of the heap in debugfs. A top-level > > > directory named "dma_heap" is created in debugfs and individual files > > > will be named after the heaps. > > > > > > > I know its debugfs, but this feels a little loosey-goosey as an uAPI. > > Well, the whole point of debugfs is that it's not really an ABI. Nothing > should ever rely on the presence of these files. > > > Is there any expected format for the show function? > > > > What would other dmabuf heaps ideally export via this interface? > > I've thought about this a bit and I'm not sure it makes sense to > standardize on this. I think on one hand having a list of buffers > exported by the dma-buf heap is probably the lowest common denominator, > but then there might be a bunch of other things that are very heap- > specific that some heap might want to export. > > > Is there some consistent dma_heap-ish concept for it to justify it > > being under a dma_heap directory, and not just an independent debugfs > > file for the driver implementing the dmabuf heap? > > Well, I think just the fact that it's a dma-heap would qualify its > corresponding debugfs to be in a well-known location. We could of course > pick some arbitrary location, but that's just a recipe for chaos because > then everybody puts these whereever they want. There's really no > standard place for driver-specific debugfs files to go, so putting it > into some "subsystem"-specific directory seems like the better option.
Ok, I guess I was thinking if the files are organizationally cohesive to be under the dma-heap directory, they ought to have some consistency between them. But I can see your perspective here that organizing the driver specific debug files in a directory helps with folks finding and identifying it. Thanks for clarifying! -john
