Online proceedings - EDA Publishing Association

7-9 October 2009, Leuven, Belgium
High-Level Thermal Profiling of Mobile Applications
Marius Marcu
“Politehnica” University of Timisoara
2 V. Parvan Blv.
Abstract- Power consumption and heat dissipation are the
major factors that limit the performance and mobility of battery
powered devices. As they become key elements in the design of
mobile devices and their applications, different power and
thermal management strategies have been proposed and
implemented during the last years in order to overcome the
mobility limitation due to the battery lifetime. These design
strategies are usually implemented at the lower levels of the
systems, but one research direction in software development is to
implement thermal and power control techniques at the higher
levels of the system. The work presented in this paper evaluates
the thermal response of the mobile system components related to
the running software applications.
I. INTRODUCTION
Thermal behavior is expected to be an important design
consideration for the next generation of microprocessors,
both for high-performance computing and mobile computing
[1]. Proper thermal management depends on two major
elements: thermal packaging and thermal management.
Thermal packaging includes heat-sink properly mounted to
the processor and effective fans directing airflow through the
system chassis [2]. Dynamic thermal management (DTM)
strategies are used to reduce packaging cost without
unnecessarily limiting performance, the package is designed
for the worst typical application and any application that
dissipate more heat should activate an alternative, run-time
thermal management technique [3].
Dynamic thermal management (DTM) has been a hot
topic in last years [4]. The purpose of DTM is to achieve
high-performance computing while maintaining the chip
below a safe temperature [5]. However DTM techniques
usually address the low-level layers in a computing system:
hardware level, BIOS level and OS level. Addressing
thermal management at higher levels of a computing system
does not replace the DTM already implemented at lower
levels, but extends these techniques to user applications and
permits applications to adapt themselves in order to reduce
the heat dissipation of the whole software and hardware
system.
The present paper tries to describe thermal profiling of
software applications. In fact we want to know the thermal
impact on different system components due to the running
software applications. The final goal of our work is to
establish a set of rules for thermal-aware applications and to
implement them in mobile applications.
This section will continue with a brief description of other
recent or important papers in this research field. The authors
of [1] investigate in their work the benefits of thermal-aware
task scheduling with minimum performance degradation.
Timisoara, Romania
They consider that the task scheduler in a multi-tasking
system can use thermal metrics when running different
active tasks in order to reduce the number of cycles above
the thermal threshold allowed for the microprocessor [1].
Multicore architectures are becoming the main design
paradigm for current and future processors, including mobile
processors, because these architectures provide increased
parallelism within the energy and thermal limits needed by
such devices. The authors of [6] present an detailed study of
different DTM techniques that can be used in multicore
designs. They consider that thread migration and dynamic
voltage and frequency scaling techniques are the most
promising methods to control temperature in multicore
architectures.
Software level thermal management becomes an attractive
extension to low level management techniques. In [7] the
authors describe a software solution for temperature sensing
methodology that can be used for thermal profiling of
software applications. The temperature model is based on the
interface with some system components parameters through
performance counters.
In [8] a software framework for dynamic energy
efficiency and temperature management for computing
systems is presented. The authors address both energy and
temperature in a unified approach which combines a suite of
energy-management techniques that can be activated
individually or in groups according to a given policy. The
evaluation has shown that the proposed framework [8] is
very effective, because it delivers a 40% energy reduction
with only a 10% application slowdown.
In the core of dynamic thermal management schemes lies
accurate reading of on-die temperatures [9]. Thermal
management techniques based on on-line temperature
sensing depend on monitoring sensors placement inside the
processor chip and cores. In [9] the authors propose three
techniques to create sensor infrastructures for monitoring the
maximum temperature on a multicore system. They
investigate the number of sensors and their placement, the
number of active sensors and their selection in order to
collect and predict the maximum temperature of each core in
the microprocessor.
An important aspect addressed also in our work is the
unification of power consumption and thermal management
[8,10]. The paper is organized as follows. In the next section
we define the thermal profiling concepts and the software
tool we implemented to characterize the thermal behavior of
a mobile device and its applications. Some experimental
results are presented in Section 3 and Section 4 contains our
concluding remarks.
©EDA Publishing/THERMINIC 2009 144
ISBN: 978-2-35500-010-2