Today's architecture seminar: Milo Martin's practice interview talk

[Alaa Alameldeen <alaa@xxxxxxxxxxx>]

Today at 4 PM in 1325 CS, Milo Martin is going to give his academic
practice interview talk. Please try to attend and give Milo 
feedback. Thanks to the pl-seminar folks for allowing us to use their
room, and they are welcome to attend as well.  

The title and abstract are attached.

-Alaa


Computer  Architecture  Seminar:  Milo  Martin,  UW-Madison,  
"Token Coherence: Enabling Faster Multiprocessor Servers by 
Decoupling Performance  and  Correctness"

This seminar is a practice academic interview talk. I'd welcome and 
appreciate any feedback on my talk, especially from non-architects.

Token Coherence is a new hardware technique for increasing  the  performance
of  commercial  server workloads (e.g., database and web serving) running on
moderate-sized multiprocessors. These shared-memory  multiprocessor  servers
use cache-coherence protocols to provide the abstraction of a unified shared
memory, and the performance of existing cache-coherence  protocols  is  
constrained either by requiring global message ordering or by the extra 
latency added by request indirections.

Token Coherence provides a framework for avoiding these performance  
bottlenecks by decoupling correctness requirements from performance
optimizations. In this new framework, the correctness substrate provides
strong correctness invariants  involving  token counting that guarantee 
correct behavior in all cases (without requiring ordering and
indirections). A separate  performance protocol  provides  high
performance  in the common case, relying on a more conservative (less
efficient) mechanism only in rare  cases.  This  approach
(1)  avoids  request ordering, (2) reduces indirections, 
(3) enables predictive and adaptive techniques that can further 
increase performance and scalability,  and  (4)  may reduce the 
verification effort required to eliminate protocol design errors that 
can cause data corruption.