There is a compilation error: ../lib/librte_eal/linuxapp/eal/eal_memalloc.c: In function ‘alloc_seg’: ../lib/librte_eal/linuxapp/eal/eal_memalloc.c:619:3: error: ‘map_offset’ may be used uninitialized in this function
13/07/2018 12:27, Anatoly Burakov: > Implement the final piece of the in-memory mode puzzle - enable running > DPDK entirely in memory, without creating any files. > > To do it, use mmap with MAP_HUGETLB and size flags to enable DPDK to work > without hugetlbfs mountpoints. In order to enable this, a few things needed > to be changed. > > First of all, we need to allow empty hugetlbfs mountpoints in > hugepage_info, and handle them correctly (by not trying to create any > files and lock any directories). > > Next, we need to reorder the mapping sequence, because the page is not > really allocated until the page fault, and we cannot get its IOVA > address before we trigger the page fault. > > Finally, decide at compile time whether we are going to be supporting > anonymous hugepages or not, because we cannot check for it at runtime. > > Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com> > --- > > Notes: > RFC->v1: > - Drop memfd and instead use mmap() with MAP_HUGETLB. This will drop the > kernel requirements down to 3.8, and does not impose any restrictions > glibc (as far as i known). > > Unfortunately, there's a bit of an issue with this approach, because > mmap() is stupid and will happily ignore unsupported arguments. This > means that if the binary were to be compiled on a 3.8+ kernel but run > on a pre-3.8 kernel (such as currently supported minimum of 3.2), then > most likely the memory would be allocated using regular pages, causing > unthinkable performance degradation. No solution to this problem is > currently known to me.
