NECST Friday Talk
A Software Cache Partitioning system for Hash-based Caches
Alberto Scolari
DEIB PhD student in Computer Architecture - Politecnico di Milano
DEIB - NECST Meeting Room (Building 20, basement floor)
February 17th, 2017
12.00 pm
Contact:
Marco Santambrogio
Research Line:
System architectures
Alberto Scolari
DEIB PhD student in Computer Architecture - Politecnico di Milano
DEIB - NECST Meeting Room (Building 20, basement floor)
February 17th, 2017
12.00 pm
Contact:
Marco Santambrogio
Research Line:
System architectures
Sommario
Contention on the shared Last Level Cache (LLC) can have a fundamental negative impact on the performance of applications executed on modern multicores. An interesting software approach to address LLC contention issues is based on page coloring, which is a software technique that attempts to achieve performance isolation by partitioning a shared cache through careful memory management. The key assumption of traditional page coloring is that the cache is physically addressed. However, recent multicore architec- tures (e.g., Intel Sandy Bridge and later) switched from a physical addressing scheme to a more complex scheme that involves a hash function. Traditional page coloring is ineffective on these recent architectures.
In this work, we extend page coloring to work on these recent architectures by proposing a mechanism able to handle their hash-based LLC addressing scheme. Just as for traditional page coloring, the goal of this new mechanism is to deliver performance isolation by avoiding contention on the LLC, thus enabling predictable performance. We implement this mechanism in the Linux kernel and we evaluate it using several benchmarks from the SPEC CPU2006 and PARSEC 3.0 suites. Results show that our solution is able to deliver performance isolation to concurrently running applications by enforcing partitioning of a Sandy Bridge LLC, which traditional page coloring techniques are not able to handle.
In this work, we extend page coloring to work on these recent architectures by proposing a mechanism able to handle their hash-based LLC addressing scheme. Just as for traditional page coloring, the goal of this new mechanism is to deliver performance isolation by avoiding contention on the LLC, thus enabling predictable performance. We implement this mechanism in the Linux kernel and we evaluate it using several benchmarks from the SPEC CPU2006 and PARSEC 3.0 suites. Results show that our solution is able to deliver performance isolation to concurrently running applications by enforcing partitioning of a Sandy Bridge LLC, which traditional page coloring techniques are not able to handle.