On 8/12/22 14:34, Christian König wrote: > > > Am 10.08.22 um 20:53 schrieb Dmitry Osipenko: >> On 8/10/22 21:25, Christian König wrote: >>> Am 10.08.22 um 19:49 schrieb Dmitry Osipenko: >>>> On 8/10/22 14:30, Christian König wrote: >>>>> Am 25.07.22 um 17:18 schrieb Dmitry Osipenko: >>>>>> This patch moves the non-dynamic dma-buf users over to the dynamic >>>>>> locking specification. The strict locking convention prevents >>>>>> deadlock >>>>>> situation for dma-buf importers and exporters. >>>>>> >>>>>> Previously the "unlocked" versions of the dma-buf API functions >>>>>> weren't >>>>>> taking the reservation lock and this patch makes them to take the >>>>>> lock. >>>>>> >>>>>> Intel and AMD GPU drivers already were mapping imported dma-bufs >>>>>> under >>>>>> the held lock, hence the "locked" variant of the functions are added >>>>>> for them and the drivers are updated to use the "locked" versions. >>>>> In general "Yes, please", but that won't be that easy. >>>>> >>>>> You not only need to change amdgpu and i915, but all drivers >>>>> implementing the map_dma_buf(), unmap_dma_buf() callbacks. >>>>> >>>>> Auditing all that code is a huge bunch of work. >>>> Hm, neither of drivers take the resv lock in map_dma_buf/unmap_dma_buf. >>>> It's easy to audit them all and I did it. So either I'm missing >>>> something or it doesn't take much time to check them all. Am I really >>>> missing something? >>> Ok, so this is only changing map/unmap now? >> It also vmap/vunmap and attach/detach: In the previous patch I added the >> _unlocked postfix to the func names and in this patch I made them all to >> actually take the lock. > > > Take your patch "[PATCH v2 2/5] drm/gem: Take reservation lock for > vmap/vunmap operations" as a blueprint on how to approach it. > > E.g. one callback at a time and then document the result in the end. Yeah, I'll do it for v3. I'm vaguely recalling that there was a problem when I wanted to split this patch in the past, but don't remember what it was.. maybe that problem is gone now, will see :) -- Best regards, Dmitry
