On 03-Mar-18 1:45 PM, Anatoly Burakov wrote:
This patchset introduces dynamic memory allocation for DPDK (aka memory hotplug). Based upon RFC submitted in December [1].Dependencies (to be applied in specified order): - IPC bugfixes patchset [2] - IPC improvements patchset [3] - IPC asynchronous request API patch [4] - Function to return number of sockets [5] Deprecation notices relevant to this patchset: - General outline of memory hotplug changes [6] - EAL NUMA node count changes [7] The vast majority of changes are in the EAL and malloc, the external API disruption is minimal: a new set of API's are added for contiguous memory allocation for rte_memzone, and a few API additions in rte_memory due to switch to memseg_lists as opposed to memsegs. Every other API change is internal to EAL, and all of the memory allocation/freeing is handled through rte_malloc, with no externally visible API changes. Quick outline of all changes done as part of this patchset: * Malloc heap adjusted to handle holes in address space * Single memseg list replaced by multiple memseg lists * VA space for hugepages is preallocated in advance * Added alloc/free for pages happening as needed on rte_malloc/rte_free * Added contiguous memory allocation API's for rte_memzone * Integrated Pawel Wodkowski's patch for registering/unregistering memory with VFIO [8] * Callbacks for registering memory allocations * Multiprocess support done via DPDK IPC introduced in 18.02 The biggest difference is a "memseg" now represents a single page (as opposed to being a big contiguous block of pages). As a consequence, both memzones and malloc elements are no longer guaranteed to be physically contiguous, unless the user asks for it at reserve time. To preserve whatever functionality that was dependent on previous behavior, a legacy memory option is also provided, however it is expected (or perhaps vainly hoped) to be temporary solution. Why multiple memseg lists instead of one? Since memseg is a single page now, the list of memsegs will get quite big, and we need to locate pages somehow when we allocate and free them. We could of course just walk the list and allocate one contiguous chunk of VA space for memsegs, but this implementation uses separate lists instead in order to speed up many operations with memseg lists. For v1, the following limitations are present: - FreeBSD does not even compile, let alone run - No 32-bit support - There are some minor quality-of-life improvements planned that aren't ready yet and will be part of v2 - VFIO support is only smoke-tested (but is expected to work), VFIO support with secondary processes is not tested; work is ongoing to validate VFIO for all use cases - Dynamic mapping/unmapping memory with VFIO is not supported in sPAPR IOMMU mode - help from sPAPR maintainers requested Nevertheless, this patchset should be testable under 64-bit Linux, and should work for all use cases bar those mentioned above. [1] http://dpdk.org/dev/patchwork/bundle/aburakov/Memory_RFC/ [2] http://dpdk.org/dev/patchwork/bundle/aburakov/IPC_Fixes/ [3] http://dpdk.org/dev/patchwork/bundle/aburakov/IPC_Improvements/ [4] http://dpdk.org/dev/patchwork/bundle/aburakov/IPC_Async_Request/ [5] http://dpdk.org/dev/patchwork/bundle/aburakov/Num_Sockets/ [6] http://dpdk.org/dev/patchwork/patch/34002/ [7] http://dpdk.org/dev/patchwork/patch/33853/ [8] http://dpdk.org/dev/patchwork/patch/24484/
For those wanting to test this patchset, there is now a github tree with all of the dependent patches applied:
https://github.com/anatolyburakov/dpdk -- Thanks, Anatoly
