PPT-Loose-Ordering Consistency for Persistent Memory

Youyou Lu 1 Jiwu Shu 1 Long Sun 1 Onur Mutlu 2 1 Tsinghua University 2 Carnegie Mellon University Problem Strict write ordering required for storage consistency dramatically degrades performance in persistent memory. Weak Consistency Models. Madan Musuvathi. Research in Software Engineering. Microsoft Research. Hard to program. Hard to test. Hard to debug. General consensus: trade consistency for . Availability. Performance. Steven . Pelley. , Peter M. Chen, Thomas F. . Wenisch. University of Michigan. Nonvolatile memory (NVRAM) recovery. 2. Writes unordered!. Constrain persist order for correctness, . but reorder for performance. Anshuman Gupta. September 18, 2009. 1. Multi-core Processors are . abundant. Multi-cores increase the compute resources on the chip without increasing hardware complexity. Keeps power consumption within the budgets.. Emerging Persistent . Memory Technologies. Phase change memory. Heat changes memory . cells . between crystalline and amorphous states. Spin torque memory/MRAM. Magnetic layers within . m. emory cells . S. anketh. Nalli. , Swapnil . Haria. , . Michael . M. . Swift. , . Mark D. Hill, H. aris. Volos*, Kimberly Keeton*. University of Wisconsin-Madison &. *Hewlett-Packard . Labs. Facilitate better system support for Persistent . Koo. sm.koo1989@gmail.com. “NVM Duet: Unified Working Memory and Persistent Store Architecture”. Ren-. Shuo. Liu, De-Yu Shen, Chia-Lin Yang, Shun-. Chih. Yu, Cheng-Yuan Michael Wang. Index. Background. COS 518: . Advanced Computer Systems. Lecture . 3. Michael Freedman. Let’s say A and B send an op. . All readers see A . →. B ?. All . readers see . B. . → A ? . Some see . A . → B . and others . Emerging Persistent . Memory Technologies. Phase change memory. Heat changes memory . cells . between crystalline and amorphous states. Spin torque memory/MRAM. Magnetic layers within . m. emory cells . S. anketh. Nalli. , Swapnil . Haria. , . Michael . M. . Swift. , . Mark D. Hill, H. aris. Volos*, Kimberly Keeton*. University of Wisconsin-Madison &. *Hewlett-Packard . Labs. Facilitate better system support for Persistent . Aasheesh Kolli. Jeff Rosen. Stephan . Diestelhorst. Ali . Saidi. . Steven Pelley. Sihang. Liu. Peter M. Chen. Thomas F. . Wenisch. MICRO 2016 - Taipei. Promise of Persistent Memory (PM). 2. Non-volatility. October 11, 2018. A.F. Cooper. Context and Motivation. How can we synchronize an asynchronous distributed system?. How do we make global state consistent? . Snapshots / checkpoints. Example: Buying a ticket on Ticketmaster. MIT’s RISCY Expedition. Andy Wright, . Sizhuo. Zhang, Thomas . Bourgeat. , Amol . Bhave. , Jamey Hicks, Arvind. Computer Science & Artificial Intelligence Lab.. Massachusetts Institute of Technology. BYTE ADDR. NONVOLATILE. PERSISTENT MEMORY. CPU. PERSISTENTMEMORY. Provides an opportunity to manipulate persistent data directly. Ld/St. NVM. FAST. BYTE ADDR. NONVOLATILE. WHAT HAPPENS WHEN . WE RUN AN APPLICATION?. COS 418: Distributed Systems. Lecture 12. Wyatt Lloyd. Outline. Network Partitions. Linearizability. CAP Theorem. Consistency Hierarchy. Network Partitions Divide Systems. Network Partitions Divide Systems.