Re: [PATCH 01/10] dma-buf: Add reference counting to dma_resv

[Matthew Brost <matthew.brost@intel.com>]

On Fri, Aug 28, 2026 at 12:17:57PM -0700, Matthew Brost wrote:
> On Fri, Aug 28, 2026 at 08:21:17PM +0200, Danilo Krummrich wrote:
> > On Thu Aug 27, 2026 at 2:38 PM CEST, =?UTF-8?q?Christian=20K=C3=B6nig?= wrote:
> > > This provides clearer ownership semantics and makes the code more
> > > maintainable by removing the embedded allocation hack.
> > 
> > Again, fundamentally disagree; please see [1] for details and reasons.
> > 
> 
> I think Christian is doing this incrementally rather than as a single
> change across the tree. The last patch [2] in the series removes
> `dma_resv_init` and the `allocated` flag. I believe that was the main
> concern, and it appears to be addressed now.
> 
> I'm taking the series for a spin now, as our CI [3] had trouble applying
> this patch. I'll let you know what my testing shows.
> 

I ran our basic CI suite and didn't see any regressions. I also ran some
eviction and shrinker tests that stress interactions with active fences
and exercise individualization paths, and those passed as well.

Matt

> [2] https://patchwork.freedesktop.org/patch/748868/?series=172875&rev=1
> [3] https://patchwork.freedesktop.org/series/172873/
> 
> > Besides that, I don't really know what to expect from the series. The cover
> > letter says "Refcounting dma_resv v2", yet there's no changelog telling people
> > what has changed since v1. On the other hand, none of the patches has a v2
> > prefix, so what is it?
> 
> Yes, change logs / cover-letter would help as Danilo likely could have
> spotted the above change.
> 
> Matt
> 
> > 
> > [1] https://lore.kernel.org/all/DJVRML4G11GZ.Z7FTZH7I1LZN@kernel.org/