Practice Interview Talk

[Trishul Chilimbi <chilimbi@xxxxxxxxxxx>]

	I will be giving this talk on Friday (2/26) in room 1325
at 4pm. This is joint work with my advisor Prof. James Larus and
co-advisor Prof. Mark Hill. In addition, this is a practice
interview talk so please be at your hostile best.

	Thanks,
	-Trishul Chilimbi

	Cache-Conscious Data Organization and Layout
        ---------------------------------------------
Abstract
     In this talk I will show that cache-conscious pointer structure
layout can improve the performance of real programs by up to 30--40%.
I will outline a wide variety of techniques for laying out pointer 
structures in languages such as C, C++, and Java. These include
completely automatic techniques that require no programmer assistance
or source code modification. 
     I will discuss one such technique--cache-conscious reorganization
using copying garbage collection that co-locates objects with high
temporal affinity in the same cache block--in detail. Measurements show
that this technique reduces cache miss rates by 21--42%, and improves
program performance by 14--37% over a conventional copying algorithm 
(Cheney). In addition it outperforms an algorithm (Wilson-Lam-Moher)
designed to improve locality at the page level by 18--31%, indicating 
that improving locality at the page level is not necessarily beneficial
at the cache level. 
	Finally, for structures comparable in size to a cache block, 
structure splitting can increase the number of hot fields that can be 
placed in a cache block. In five Java programs, structure splitting 
reduced cache miss rates 10--27% and improved performance 6--18%
beyond the benefits of cache-conscious reorganization.