Changeset 05e33f5 for doc/theses/thierry_delisle_PhD/thesis/text

Timestamp:

Apr 11, 2022, 8:49:43 PM (3 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, ast-experimental, enum, master, pthread-emulation, qualifiedEnum

Children:

e88c2fb

Parents:

13888c0e

Message:

Added a section on fairness goals to chapter 3

File:

• doc/theses/thierry_delisle_PhD/thesis/text/core.tex (modified) (1 diff)

doc/theses/thierry_delisle_PhD/thesis/text/core.tex

@@ -32 +32 @@
         \item Faster than other schedulers that have equal or better fairness.
 \end{itemize}
+
+\subsection{Fairness Goals}
+For this work fairness will be considered as having two strongly related requirements: true starvation freedom and ``fast'' load balancing.
+
+\paragraph{True starvation freedom} is more easily defined: As long as at least one \proc continues to dequeue \ats, all read \ats should be able to run eventually.
+In any running system, \procs can stop dequeing \ats if they start running a \at that will simply never park.
+Traditional workstealing schedulers do not have starvation freedom in these cases.
+Now this requirement begs the question, what about preemption?
+Generally speaking preemption happens on the timescale of several milliseconds, which brings us to the next requirement: ``fast'' load balancing.
+
+\paragraph{Fast load balancing} means that load balancing should happen faster than preemption would normally allow.
+For interactive applications that need to run at 60, 90, 120 frames per second, \ats having to wait for several millseconds to run are effectively starved.
+Therefore load-balancing should be done at a faster pace, one that can detect starvation at the microsecond scale.
+With that said, this is a much fuzzier requirement since it depends on the number of \procs, the number of \ats and the general load of the system.
 
 \subsection{Fairness vs Scheduler Locality} \label{fairnessvlocal}