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Passive remote memory remains the holy grail of disaggregation. Most existing systems for disaggregated memory either use remote memory simply as a backing store, or design special-purpose data structures that require some amount of processing co-resident with the remote memory to manage and apply updates. The few proposals for truly passive remote memory perform well only with read-mostly workloads, rapidly deteriorating in the face of even low levels of write contention. We propose to leverage in-network devices (specifically, a programmable top-of-rack switch) to serialize remote memory accesses and resolve any write conflicts in flight. Our prototype is able to completely avoid write contention in the recently published Clover disaggregated key/value store, delivering a performance boost of almost 50% on our testbed under a mixed read/write workload. 

Multiple vendors have recently released SmartNICs that provide both special-purpose accelerators and programmable processing cores that allow increasingly sophisticated packet processing tasks to be offloaded from general-purpose CPUs. Indeed, leading data-center operators have designed and deployed SmartNICs at scale to support both network virtualization and application-specific tasks. Unfortunately, cloud providers have not yet opened up the full power of these devices to tenants, as current runtimes do not provide adequate isolation between individual applications running on the SmartNICs themselves. We introduce FairNIC, a system to provide performance isolation between tenants utilizing the full capabilities of a commodity SoC SmartNIC. We implement FairNIC on Cavium LiquidIO 2360s and show that we are able to isolate not only typical packet processing, but also prevent MIPS-core cache pollution and fairly share access to fixed-function hardware accelerators. We use FairNIC to implement NIC-accelerated OVS and key/value store applications and show that they both can cohabitate on a single NIC using the same port, where the performance of each is unimpacted by other tenants. We argue that our results demonstrate the feasibility of sharing SmartNICs among virtual tenants, and motivate the development of appropriate security isolation mechanisms.