On Tue, Apr 08, 2025 at 06:14:55PM +0300, Damir Chanyshev wrote: > On Tue, Apr 8, 2025 at 6:06???PM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > The pci_p2pdma_whitelist[] is only updated when somebody tests a > > platform and determines that its RC can route peer-to-peer > > transactions between separate Root Ports. This routing is not > > required by the PCIe spec, so we can't assume that all platforms > > support it. > > For the testing, is simple rdma ping-pong sufficient? Or a more > specific testing tool? > Unfortunately I don't have a fancy pcie hardware analyzer. You should test that performance is satisfactory for you needs. There are claims that older Intel CPUs have poor p2pdma performance: https://lore.kernel.org/all/e2c56983-0111-4132-ae17-0095aa33fd2d@xxxxxxxxxxxx/ Thanks, Lukas
