We have discussed for years ways to create more reliable ways to allocate large contiguous memory segments and to avoid fragmentation. This is an ad hoc scheme based on reservation of higher order pages in the page allocator. It is fully transparent and integrated into the page allocator. This approach goes back to the meeting on contiguous memory at the Plumbers conference in 2017 and the effort by Guy and Mike Kravetz to establish and API to map contiguous memory segments into user space. Reservations will allow the contiguous memory allocations to work even after the system has run for a considerable time. Contiguous memory is also important for general system performance. F.e. slab allocators can be made to use large frames in order to optimize performance. See patch 1. Other use cases are jumbo frames or device driver specific allocations. For more on this see Mike Kravetz patches in particular Mike Kravetz MMAP CONTIG flag support at https://lkml.org/lkml/2017/10/3/992 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
