Hi Xiuqi, On 2018/5/31 20:14, Xie XiuQi wrote: > A numa system may return node which is not online. > For example, a numa node: > 1) without memory > 2) NR_CPUS is very small, and the cpus on the node are not brought up
I think adding detail info will be easy to be understood: - NUMA node will be built if CPUs and (or) memory are valid on this NUMA node; - But if we boot the system with memory-less node and also with CONFIG_NR_CPUS less than CPUs in SRAT, for example, 64 CPUs total with 4 NUMA nodes, 16 CPUs on each NUMA node, if we boot with CONFIG_NR_CPUS=48, then we will not built numa node for node 3, but with devices on that numa node, alloc memory will be panic because NUMA node 3 is not a valid node. > > In this situation, we use NUMA_NO_NODE to avoid oops. [snip] > > Xie XiuQi (2): > arm64: avoid alloc memory on offline node > drivers: check numa node's online status in dev_to_node I think we still missing devices like SMMU, ITS, so how about check the numa node online in the core memory allocation such as kmalloc_node()? Thanks Hanjun
