On Tue, Sep 23, 2025 at 02:09:36PM -0300, Jason Gunthorpe wrote: > On Sat, Sep 20, 2025 at 06:47:27PM -0600, Keith Busch wrote: > > > > One other thing to note, this was runing on arm64 platform using smmu > > configured with 64k pages. If your iommu granule is 4k instead, we > > wouldn't use the blk_dma_map_direct path. > > I spent some time looking to see if I could guess what this is and > came up empty. It seems most likely we are leaking a dma mapping > tracking somehow? The DMA API side is pretty simple here though.. Yeah, nothing stood out to me here either. > Not sure the 64k/4k itself is a cause, but triggering the non-iova > flow is probably the issue. > > Can you check the output of this debugfs: I don't have a system in this state at the moment, so we checked previous logs on machines running older kernels. It's extermely uncommon, but this error was happening prior to this series, so I don't think this introduced any new problem here. I'll keeping looking, but I don't think we'll make much progress if I can't find a more reliable reproducer. Thanks!
