Am 24.01.2018 um 11:32 schrieb Chunming Zhou: > On 2018å¹´01æ??24æ?¥ 17:49, Christian König wrote: >> [SNIP] >> Nope, as I wrote that won't work. You must improve the detection if >> we need coherent or not coherent allocation. > But how to differentiate coherent or not coherent allocation? check if > max io address of system memory under 40bits pcie address space? Do > you know how to get the max io address of system memory? Well that is a good question, which nobody had an answer for so far (and a couple of people already looked into it). We could start by checking if max_pfn is <= the 40bits limit or if IOMMU is enabled instead of SWIOTLB. Regards, Christian.
