From fca59bea770346cf1c1f9b0e00cb48a61b44a8f3 Mon Sep 17 00:00:00 2001
From: Harald Welte <laforge@gnumonks.org>
Date: Sun, 25 Oct 2015 21:00:20 +0100
Subject: import of old now defunct presentation slides svn repo

---
 .../OLS2005/seelam/seelam-abstract.tex             | 56 ++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 2005/flow-accounting-ols2005/OLS2005/seelam/seelam-abstract.tex

(limited to '2005/flow-accounting-ols2005/OLS2005/seelam/seelam-abstract.tex')

diff --git a/2005/flow-accounting-ols2005/OLS2005/seelam/seelam-abstract.tex b/2005/flow-accounting-ols2005/OLS2005/seelam/seelam-abstract.tex
new file mode 100644
index 0000000..26070b0
--- /dev/null
+++ b/2005/flow-accounting-ols2005/OLS2005/seelam/seelam-abstract.tex
@@ -0,0 +1,56 @@
+
+%         Registration              Enhancements to Linux I/O Scheduling      
+%  [2]Register/Submit Proposal Seetharami R Seelam (seelam@cs.utep.edu)       
+
+The Linux 2.6 release provides four I/O        
+schedulers: deadline, anticipatory, noop, and  
+completely fair queuing (CFQ), along with an   
+option to select one of these four at boot     
+time. The selection is based on \textit{a priori}       
+knowledge of the workload, hardware            
+configuration of the system, and the file      
+system, among other factors. The anticipatory  
+scheduler (AS) is the default. Although the AS 
+performs well under many situations, we have   
+identified cases, under certain combinations   
+of workloads, where the AS leads to starvation 
+of processes. To mitigate this problem, we     
+implemented an extension to the AS (called     
+Cooperative AS or CAS) and compared its        
+performance with the other four schedulers.    
+This paper briefly describes the AS and the    
+related deadline scheduler, highlighting their 
+shortcomings; in addition, it gives a detailed 
+description of the CAS. We report performance  
+of all five schedulers on a set of workloads,  
+which represent a wide range of I/O behavior.  
+The study shows that (1) the CAS has an order  
+of magnitude improvement in performance in     
+cases where the AS leads to starvation and (2) 
+in several cases the CAS has performance       
+comparable to that of the other schedulers.    
+But, as the literature and this study reports, 
+no one scheduler can provide the best possible 
+performance for all workloads; accordingly,    
+Linux provides four from which to select. Even 
+when dealing with just four I/O schedulers, in 
+systems that service concurrent workloads with 
+different I/O behaviors, \textit{a priori} selection of 
+the scheduler with the best possible           
+performance can be an intricate task. Dynamic  
+selection based on workload needs, system      
+configuration, and other parameters can        
+address this challenge. Accordingly, we are    
+developing metrics and heuristics that can be  
+used for this purpose. The paper concludes     
+with a description of our efforts in this      
+direction, in particular, we present a         
+characterization function based on metrics     
+related to system behavior and I/O requests    
+that can be used to measure and compare        
+scheduling algorithm performance. This         
+characterization function can be used to       
+dynamically select an appropriate scheduler    
+based on observed system behavior.             
+
+
-- 
cgit v1.2.3

