This presentation talks about the recent trends in operating system, memory hierarchies, and file systems.

1. Recent Trends in Memory Technologies and OS
Pradeeban Kathiravelu
INESC-ID Lisboa
Instituto Superior T´ecnico, Universidade de Lisboa
Lisbon, Portugal
Modern Operating System Kernels – Presentation 2.
April 27, 2015.
Pradeeban Kathiravelu (IST-ULisboa) NSOM 1 / 8

2. NVM+DRAM
DRAM and Future..
Pradeeban Kathiravelu (IST-ULisboa) NSOM 2 / 8

3. NVM+DRAM
DRAM + Non-Volatile Memory (NVM) = WIN!
Why not just replace DRAM with Flash?
+++ of Flash
Less cost/bit.
Less power consuming.
Less space consuming.
— of Flash
Erase before Write. Erase blocks; not just words.
Less endurance. Die fast in the writing speed of the main memory.
Slow write.
Read timing - NAND flash reads entire page. NOR flash similar to
DRAM (though at lower bandwidths).
Pradeeban Kathiravelu (IST-ULisboa) NSOM 3 / 8

4. Hare
What is an Operating System?
Pradeeban Kathiravelu (IST-ULisboa) NSOM 4 / 8

5. Hare
What is an Operating System?
Figure : What Defines a Computer Operating System?1
1
http://www.explainxkcd.com/wiki/index.php/1508:_Operating_Systems
Pradeeban Kathiravelu (IST-ULisboa) NSOM 5 / 8

6. Hare
What is an Operating System? [2]
Pradeeban Kathiravelu (IST-ULisboa) NSOM 6 / 8

7. Hare
Portable Operating System Interface (POSIX)
Fully or Mostly POSIX-Compliant Operating Systems
IBM AIX.
Integrity.
Solaris, OpenSolaris, ..
OS X Yosemite.
BeOS, Haiku, ..
FreeBSD, OpenBSD, NetBSD, ..
Most Linux Distributions.
MINIX.
. . .
Pradeeban Kathiravelu (IST-ULisboa) NSOM 7 / 8

8. Hare
Hare File System for Non-Cache-Coherent Multicores
Pradeeban Kathiravelu (IST-ULisboa) NSOM 8 / 8

9. Hare
References
Mogul, J. C., Argollo, E., Shah, M. A., & Faraboschi, P. (2009, May).
Operating System Support for NVM+ DRAM Hybrid Main Memory.
In HotOS.
Gruenwald III, C., Sironi, F., Kaashoek, M. F., & Zeldovich, N. (2015,
April). Hare: a file system for non-cache-coherent multicores. In
Proceedings of the Tenth European Conference on Computer Systems
(p. 30). ACM.
Silberschatz, A., Galvin, P. B., Gagne, G., & Silberschatz, A. (1998).
Operating system concepts (Vol. 4). Reading: Addison-Wesley.
Rom´an, M., Hess, C., Cerqueira, R., Ranganathan, A., Campbell, R.
H., & Nahrstedt, K. (2002). A middleware infrastructure for active
spaces. IEEE pervasive computing, 1(4), 74-83.
Thank you!
Pradeeban Kathiravelu (IST-ULisboa) NSOM 9 / 8