On Thu, Jul 20, 2023 at 10:02:38AM +0200, Petr Tesařík wrote: > On Thu, 20 Jul 2023 08:47:44 +0200 > Christoph Hellwig <hch@xxxxxx> wrote: > > > Any reason this can't just do a list_empty_careful on the list > > instead of adding yet another field that grows struct device? > > On which list? dev->dma_io_tlb_mem->pools? > > The dma_io_tlb_pools list only contains transient pools, but a device > may use bounce buffers from a regular pool. Oh, true. > The dma_io_tlb_mem.pools list will always be non-empty, unless the > system runs without SWIOTLB. > > On a system which does have a SWIOTLB, the flag allows to differentiate > between devices that actually use bounce buffers and devices that do > not (e.g. because they do not have any addressing limitations). Ok.
