Changeset a9e10e2 for doc/theses/colby_parsons_MMAth

Timestamp:

Jul 5, 2023, 5:34:10 PM (17 months ago)

Author:

caparsons <caparson@…>

Branches:

master

Children:

2f26b841, c8bf1b5

Parents:

7c4416a

Message:

small update to end of work stealing section

File:

• doc/theses/colby_parsons_MMAth/text/actors.tex (modified) (1 diff)

doc/theses/colby_parsons_MMAth/text/actors.tex

@@ -682 +682 @@
 In theory, if this race occurs multiple times consecutively \ie a thief steals, dereferences stolen mailbox pointer, is interrupted and stolen from, etc., this scenario can cascade across multiple workers all attempting to gulp from one mailbox.
 The @being_processed@ flag ensures correctness even in this case, and the chance of a cascading scenario across multiple workers is even rarer.
-% The rarity is why this mechanism is zero-victim-cost in practice but not in theory.
-By collecting statistics on failed gulps due to the @being_processed@ flag, this contention occurs $\approx$0.05\% of the time when a gulp occurs (1 in every 2000 gulps).
-\PAB{You need to explain the experiment that gathered this information.}
-Hence, the claim is made that this stealing mechanism has (probabilistically) zero-victim-cost in practice.
+It is straightforward to count the number of missed gulps due to the @being_processed@ flag at runtime.
+With the exception of the repeat benchmark, the median count of missed gulps for each number of cores for all benchmarks presented in Section~\ref{s:actor_perf} is \emph{zero}.
+The repeat benchmark is an example the pathological case described earlier where there is too little work and too many workers.
+In the repeat benchmark one actor has the majority of the workload, and no other actor has a consistent workload which results in rampant stealing.
+None of the work stealing actor systems compared in this work perform well on the repeat benchmark.
+Hence, the claim is made that this stealing mechanism has a (probabilistically) zero-victim-cost in practice.
 
 \subsection{Queue Pointer Swap}\label{s:swap}