Cephalocon 2022

With more and more fast devices (especially persistent memory) equipped in data center, there is great pressure on CPU to drive those devices (e.g., Intel Optane DC persistent memory) for persistency purpose under heavy workloads. Because there is no DMA related capability provided by persistent memory compared with those hdds and SSDs. And the same issue also exists in Ceph while using persistent memory. We would like to address such pain points by leveraging memory offloading devices (e.g., DSA). So generally in this talk, we will talk: 1) While persistent memory integration is not very successful in Ceph due to the high CPU overhead while performing I/O operations on persistency device; 2) We introduce the memory offloading devices (e.g., DSA) in order to offload the CPU pressure while doing I/Os; 3) We will describe the main change in pmem device (i.e., src/blk/pmemdevice.cc) and state how we can achieve the offloading including the challenges. 4) We would like to have some early performance results if Intel's SPR platform is available in public.