eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
12
10.4230/DagSemProc.10071.1
article
10071 Abstracts Collection – Scheduling
Albers, Susanne
Baruah, Sanjoy K.
Möhring, Rolf H.
Pruhs, Kirk
From 14.02. to 19.02.2010, the Dagstuhl Seminar 10071 ``Scheduling '' was held
in Schloss Dagstuhl-Leibniz Center for Informatics.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.1/DagSemProc.10071.1.pdf
Scheduling
real-time
complexity
approximation algorithms
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
2
10.4230/DagSemProc.10071.2
article
10071 Executive Summary – Scheduling
Albers, Susanne
Baruah, Sanjoy K.
Möhring, Rolf H.
Pruhs, Kirk
The primary objectives of this seminar were to bring together leading
researchers working on scheduling problems in three different research
communities – operations research, theoretical computer science, and
real-time systems – to expose each community to the important problems
addressed by the other communities; to enable and encourage cooperation
among the researchers; and to facilitate a transfer of solution techniques
from each community to the others.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.2/DagSemProc.10071.2.pdf
Scheduling
real-time
complexity
approximation algorithms
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
24
10.4230/DagSemProc.10071.3
article
10071 Open Problems – Scheduling
Anderson, Jim
Andersson, Björn
Azar, Yossi
Bansal, Nikhil
Bini, Enrico
Chrobak, Marek
Correa, José
Cucu-Grosjean, Liliana
Davis, Rob
Easwaran, Arvind
Edmonds, Jeff
Funk, Shelby
Gopalakrishnan, Sathish
Hoogeveen, Han
Mathieu, Claire
Megow, Nicole
Naor, Seffi
Pruhs, Kirk
Queyranne, Maurice
Rosén, Adi
Schabanel, Nicolas
Sgall, Jiří
Sitters, René
Stiller, Sebastian
Uetz, Marc
Vredeveld, Tjark
Woeginger, Gerhard J.
Collection of the open problems presented at the scheduling seminar.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.3/DagSemProc.10071.3.pdf
Open problems
scheduling
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
10
10.4230/DagSemProc.10071.4
article
A Stochastic Framework for Multiprocessor Soft Real-Time Scheduling
Anderson, James
Mills, Alex
Prior work has shown that the global earliest-deadline-first
(GEDF) scheduling algorithm ensures bounded deadline tardiness
on multiprocessors with no utilization loss; therefore,
GEDF may be a good candidate scheduling algorithm for
soft real-time workloads. However, such workloads are often
implemented assuming an average-case provisioning, and in
prior tardiness-bound derivations for GEDF, worst-case execution
costs are assumed. As worst-case costs can be orders
of magnitude higher than average-case costs, using a worst-case
provisioning may result in significant wasted processing
capacity. In this paper, prior tardiness-bound derivations for
GEDF are generalized so that execution times are probabilistic,
and a bound on expected (mean) tardiness is derived. It is
shown that, as long as the total expected utilization is strictly
less than the number of available processors, the expected
tardiness of every task is bounded under GEDF. The result
also implies that any quantile of the tardiness distribution is
also bounded.
The uploaded paper is from the upcoming RTAS. I would like
to hear suggestions about how to ease the assumption of
independent execution times in this analysis.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.4/DagSemProc.10071.4.pdf
GEDF
multiprocessor
tardiness
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
0
10.4230/DagSemProc.10071.5
article
Energy Efficient Scheduling via Partial Shutdown
Khuller, Samir
Li, Jian
Saha, Barna
We define a collection of new problems referred to as ``machine activation''
problems. The central framework we introduce considers a collection of M
machines (unrelated or related), with machine $i$ having an activation
cost of $a_i$.
There is also a collection of N jobs that need to be performed, and
$p_{ij}$ is the processing time of job $j$ on machine $i$.
Standard scheduling models assume that the set of machines is fixed
and all machines are available. We assume that there is an activation cost
budget of $A$
-- we would like to select a subset S of the machines to activate
with total cost $a(S)le A$ and find a schedule for the jobs on the
machines in $S$ minimizing the makespan. In this work we develop
bi-criteria approximation algorithms for this problem based on both
LP rounding and a greedy approach.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.5/DagSemProc.10071.5.pdf
Unrelated parallel machine scheduling
approximation algorithms
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
0
10.4230/DagSemProc.10071.6
article
Every Deterministic Nonclairvoyant Scheduler has a Suboptimal Load Threshold
Edmonds, Jeff
The goal is to prove a surprising lower bound for resource augmented nonclairvoyant algorithms for scheduling jobs with sublinear nondecreasing speed-up curves on multiple processors with the objective of average response time. Edmonds and Pruhs in SODA09 prove that for every $\e > 0$, there is an algorithm $\alg_{\e}$ that is $(1\!+\!\epsilon)$-speed $O({1 \over
\e2})$-competitive. A problem, however, is that this algorithm
$\alg_{\e}$ depends on $\e$. The goal is to prove that every fixed
deterministic nonclairvoyant algorithm has a suboptimal speed
threshold, namely for every (graceful) algorithm $\alg$, there is a
threshold $1\!+\!\beta_{\alg}$ that is $\beta_{\alg} > 0$ away from
being optimal such that the algorithm is $\Omega({1 \over \e
\beta_{\alg}})$ competitive with speed $(1 \!+\! \beta_{\alg}) \!+\!
\e$ and is $\omega(1)$ competitive with speed $1 \!+\! \beta_{\alg}$.
I have worked very hard on it and have felt that I was close. The
proof technique is to use Brouwer's fixed point theorem to break the
cycle of needing to know which input will be given before one can know
what the algorithm will do and needing to know what the algorithm will
do before one can know which input to give. Every thing I have can be
found at
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.6/DagSemProc.10071.6.pdf
Scheduling
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
22
10.4230/DagSemProc.10071.7
article
Optimal Mechanisms for Scheduling
Heydenreich, Birgit
Mishra, Debasis
Müller, Rudolf
Uetz, Marc
We study the design of optimal mechanisms in a setting where a service provider needs to schedule a set of non-preemptive jobs, one job at a time. Jobs need to be compensated for waiting, and waiting cost is private information. In this setting, an optimal mechanism is one that induces jobs to report truthfully their waiting cost, while minimizing the total expected compensation cost of the service provider. Here, truthful refers to Bayes-Nash implementability,
and assumes that private information is independently drawn from known distributions. We derive closed formulae for the optimal mechanism, and show that it is a modification of Smith’s ratio rule. We also show that it can be implemented in dominant strategies. Our analysis relies on a graph-theoretic interpretation of the incentive compatibility constraints. It parallels the
analysis known for auctions with single parameter agents, yet it exhibits some subtle differences.
We also consider the multi-dimensional case where also the service times of jobs are private information. We show that for this problem the optimal mechanism generally does not satisfy an independence condition known as IIA, and thus known approaches are doomed to fail.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.7/DagSemProc.10071.7.pdf
Optimal Mechanism Design
Scheduling
Job Agents
Smith's Rule
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
12
10.4230/DagSemProc.10071.8
article
Polynomial Time Algorithms for Minimum Energy Scheduling
Chrobak, Marek
Baptiste, Philippe
Dürr, Christoph
The aim of power management policies is to reduce the amount of energy consumed by computer systems while maintaining satisfactory level of performance. One common method for saving energy is to simply suspend the system during the idle times. No energy is consumed in the suspend mode. However, the process of waking up the system itself requires a certain fixed amount of energy, and thus suspending the system is beneficial only if the idle time is long enough to compensate for this additional energy expenditure. In the specific problem studied in the paper, we have a set of jobs with release times and deadlines that need to be executed on a single processor. Preemptions are allowed. The processor requires energy L to be woken up and, when it is on, it uses the energy at a rate of R units per unit of time. It has been an open problem whether a schedule minimizing the overall energy consumption can be computed in polynomial time. We solve this problem in positive, by providing an O(n5)-time
algorithm. In addition we provide an O(n4)-time algorithm for computing the minimum energy schedule when all jobs have unit length.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.8/DagSemProc.10071.8.pdf
Scheduling
algorithm
dynamic programming
energy
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
4
10.4230/DagSemProc.10071.9
article
Power-Aware Real-Time Scheduling: Models, Open Problems, and Practical Considerations
Fisher, Nathan
Power-related issues have received considerable research attention from the real-time community in the past decade. In our talk, we introduce a recent model and set of assumptions made in the recent real-time literature on energy and thermal issues; suggest two high-level open problems for power-aware real-time scheduling: {em peak-temperature minimization} and {em energy-minimization with temperature as a constraint}; and discuss practical considerations that should be considered in proposed solutions.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.9/DagSemProc.10071.9.pdf
Real-time scheduling
power-aware scheduling
sporadic tasks
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
7
10.4230/DagSemProc.10071.10
article
Recent Hardness Results for Periodic Uni-processor Scheduling
Eisenbrand, Friedrich
Rothvoss, Thomas
Consider a set of $n$ periodic tasks $ au_1,ldots, au_n$ where $ au_i$ is described
by an execution time $c_i$, a (relative) deadline $d_i$ and a period $p_i$.
We assume that jobs are released synchronously (i.e. at each multiple of $p_i$) and consider pre-emptive, uni-processor schedules.
We show that computing the response time of a task $ au_n$ in a Rate-monotonic schedule
i.e. computing
[
minleft{ r geq mid c_n + sum_{i=1}^{n-1} leftlceil frac{r}{p_i}
ight
ceil c_i leq r
ight}
]
is (weakly) $mathbf{NP}$-hard (where $ au_n$ has the lowest priority and the deadlines
are implicit, i.e. $d_i = p_i$).
Furthermore we obtain that verifying EDF-schedulability, i.e.
[
forall Q geq 0: sum_{i=1}^n left( leftlfloor frac{Q-d_i}{p_i}
ight
floor +1
ight)cdot c_i leq Q
]
for constrained-deadline tasks ($d_i leq p_i$) is weakly $mathbf{coNP}$-hard.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.10/DagSemProc.10071.10.pdf
Hardness
periodic scheduling
uni-processor scheduling
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
0
10.4230/DagSemProc.10071.11
article
Resource Sharing in Global Fixed-Priority Preemptive Multiprocessor Scheduling
Easwaran, Arvind
Andersson, Björn
In this paper we consider global fixed-priority preemptive multiprocessor scheduling of constrained-deadline sporadic tasks that share resources in a non-nested manner. We develop a novel resource-sharing protocol and a corresponding schedulability test for this system. We also develop the first schedulability analysis of priority inheritence protocol for the aforementioned system. Finally, we show that these protocols are efficient (based on the developed schedulability tests) for a class of priority-assignments called emph{reasonable} priority-assignments.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.11/DagSemProc.10071.11.pdf
Scheduling
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
9
10.4230/DagSemProc.10071.12
article
Scalably Scheduling Processes with Arbitrary Speedup Curves
Edmonds, Jeff
Pruhs, Kirk
We give a scalable ((1+\epsilon)-speed O(1)-competitive) nonclairvoyant algorithm for scheduling jobs with sublinear nondecreasing speed-up curves on multiple processors with the objective of average response time.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.12/DagSemProc.10071.12.pdf
Scheduling
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
3
10.4230/DagSemProc.10071.13
article
Scheduling periodic tasks in a hard real-time environment
Eisenbrand, Friedrich
Hähnle, Nicolai
Niemeier, Martin
Skutella, Martin
Verschae, Jose
Wiese, Andreas
We consider a real-time scheduling problem that occurs in the design
of software-based aircraft control. The goal is to distribute tasks
$ au_i=(c_i,p_i)$ on a minimum number of identical machines and to
compute offsets $a_i$ for the tasks such that no collision occurs. A
task $ au_i$ releases a job of running time $c_i$ at each time $a_i +
kcdot p_i, , k in mathbb{N}_0$ and a collision occurs if two jobs are
simultaneously active on the same machine.
We shed some light on the complexity and approximability landscape of this problem.
Although the problem cannot be approximated
within a factor of $n^{1-varepsilon}$ for any $varepsilon>0$, an interesting restriction
is much more tractable: If the periods are dividing (for each $i,j$ one has $p_i |
p_j$ or $p_j | p_i$), the problem allows for a better structured representation of solutions, which leads
to a 2-approximation. This result is tight, even asymptotically.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.13/DagSemProc.10071.13.pdf
Real-Time Scheduling
Periodic scheduling problem
Periodic maintenance problem
Approximation hardness
Approximation algorithm
eng
Schloss Dagstuhl – Leibniz-Zentrum für Informatik
Dagstuhl Seminar Proceedings
1862-4405
2010-05-03
10071
1
14
10.4230/DagSemProc.10071.14
article
The Parallel Supply Function Abstraction for a Virtual Multiprocessor
Bini, Enrico
Marko, Bertogna
Baruah, Sanjoy K.
A new abstraction --- the Parallel Supply Function (PSF) --- is
proposed for representing the computing capabilities offered by
virtual platforms implemented atop identical multiprocessors. It is
shown that this abstraction is strictly more powerful than
previously-proposed ones, from the perspective of more accurately
representing the inherent parallelism of the provided computing
capabilities. Sufficient tests are derived for determining whether
a given real-time task system, represented as a collection of
sporadic tasks, is guaranteed
to always meet all
deadlines when scheduled upon a specified virtual platform using the
global EDF scheduling algorithm.
https://drops.dagstuhl.de/storage/16dagstuhl-seminar-proceedings/dsp-vol10071/DagSemProc.10071.14/DagSemProc.10071.14.pdf
Virtual multiprocessor