All, If this was fixed in 1.7 and I missed it I apologize (but it looks from source to still be broken). I am using DPDK 1.6.0r2 (will be upgrading to 1.7.0 soon) on RHEL 6.4. I've converted the functions below to 1.7.0 names/locations since it looks to still be an issue there.
tl;dr -- to get examples/symmetric_mp to work at all I had to manually force the address used to map PCI UIO devices in the primary process which I achieved by: In eal_memory.c :: get_virtual_area(...) -- Use directly then increment internal_config.base_virtaddr instead of incrementing/adding baseaddr_offset In eal_pci_uio.c in 1.7.0 :: pci_uio_map_resource -- In the primary process, use and increment internal_config.base_virtaddr as the first argument when calling pci_uio_map_resource (instead of NULL). Background/reason: Recently I was trying to get multiprocessing with each process reading from one queue working and ran into issues with the call to mmap the memory for /dev/uioX. Even the example 'symmetric_mp' application was failing. The issue is that there are two memory regions which are mmap'd for each /dev/uioX device and the second one, in the secondary process, is being mapped to an address other than the requested address. This causes the check for pci_map_resource(...) != uio_res->maps[i].addr to fail. I tracked the reason for not using the requested address to the mmap call to create the stack for a thread created during one of (I forget which - I think eal) eal/pci/pmd_init calls which is used to handle interrupts. With DPDK compiled as a single shared library on our system the memory address handed for the second memory reach for each /dev/uioX in the primary process is right in the middle of the stack for that thread. My possible fix: use --base-virtaddr to populate the requested address for mmaping the memory for /dev/uioX I am not sure if this is safe but if it is I can submit a patch. My approach was in eal_memory.c to, rather than keep an 'offset' variable locally just increment the global base_virtaddr value each time through that loop and then use the resulting final value when doing the /dev/uioX mappings. Of course in 1.6.0r2 I also ran into the errno bug with parsing --base-virtaddr and strtoull but it looks like that was fixed in 1.7.0. Thoughts? Thanks! Stefan
