Stash: Have Your Scratchpad and Cache it Too
Event details
| Date | 27.04.2015 |
| Hour | 14:00 › 15:30 |
| Speaker | Matt Sinclair is a fourth year PhD student at the University of Illinois at Urbana-Champaign where he works in Professor Sarita Adve's research group. His research focuses on building efficient memory hierarchies for heterogeneous systems. He is a winner of a Qualcomm Innovation Fellowship. |
| Location | |
| Category | Conferences - Seminars |
Heterogeneous systems provide a natural path to energy efficiency. Given that the memory hierarchy is expected to be a dominant consumer of energy in these systems, efficient data movement is vital. However, the memory hierarchies of modern heterogeneous systems have multiple inefficiencies such as loose coupling between compute units; specialized, private memories that only exist in local address spaces; poor support for synchronization primitives; and complex memory consistency models. My work proposes an efficient and easier-to-program heterogeneous memory system where specialized memory components are tightly coupled in a unified and coherent address space. Underlying the system is a low overhead, software-driven hardware coherence protocol called DeNovo. This talk will focus on applying these ideas to a heterogeneous system with CPUs and GPUs employing scratchpads and caches. Specifically, we propose a new memory organization, stash, that combines the benefits of caches and scratchpads without incurring the downsides of either. Like a scratchpad, the stash does not incur overheads of tags, TLB accesses, and conflict misses. Like a cache, the stash is globally addressable and visible and allows for data reuse across compute kernels. With these benefits, the stash shows higher performance and lower energy than either a cache or a scratchpad, while enabling new applications for heterogeneous systems. Time permitting, I will also show how the use of the DeNovo protocol permits simpler memory consistency models than those motivated by current coherence protocols for heterogeneous systems.
Cookies and drinks will be available before the talk as from 13:45.
Cookies and drinks will be available before the talk as from 13:45.
Practical information
- Informed public
- Free
- This event is internal
Organizer
- EcoCloud
Contact
- Valérie Locca - EcoCloud