[dpdk-dev] mmap() hint address

[Gooch, Stephen]

Hello,

I have seen a case where a secondary DPDK process tries to map uio resource in which mmap() normally sends the corresponding virtual address as a hint address.  However on some instances mmap() returns a virtual address that is not the hint address, and it result in rte_panic() and the secondary process goes defunct.

This happens from time to time on an embedded device when nr_hugepages is set to 128, but never when nr_hugepage is set to 256 on the same device.    My question is, if mmap() can find the correct memory regions when hugepages is set to 256, would it not require less resources (and therefore be more likely to pass) at a lower value such as 128?

Any ideas what would cause this mmap() behavior at a lower nr_hugepage value?

- Stephen