Ignore:
Timestamp:
Jan 22, 2018, 3:09:01 PM (6 years ago)
Author:
Aaron Moss <a3moss@…>
Branches:
ADT, aaron-thesis, arm-eh, ast-experimental, cleanup-dtors, deferred_resn, demangler, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, pthread-emulation, qualifiedEnum, resolv-new, with_gc
Children:
e23d20b
Parents:
326cd2b (diff), 4bf3b2b (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
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Message:

Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc

File:
1 edited

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  • doc/proposals/concurrency/text/results.tex

    r326cd2b r9cdfb4d0  
    3838
    3939\section{Micro Benchmarks}
    40 All benchmarks are run using the same harness to produce the results, seen as the \code{BENCH()} macro in the following examples. This macro uses the following logic to benchmark the code :
     40All benchmarks are run using the same harness to produce the results, seen as the \code{BENCH()} macro in the following examples. This macro uses the following logic to benchmark the code:
    4141\begin{pseudo}
    42 #define BENCH(run, result)
    43         before = gettime();
    44         run;
    45         after  = gettime();
     42#define BENCH(run, result) \
     43        before = gettime(); \
     44        run; \
     45        after  = gettime(); \
    4646        result = (after - before) / N;
    4747\end{pseudo}
    … …  
    4949
    5050\subsection{Context-Switching}
    51 The first interesting benchmark is to measure how long context-switches take. The simplest approach to do this is to yield on a thread, which executes a 2-step context switch. In order to make the comparison fair, coroutines also execute a 2-step context-switch (\gls{uthread} to \gls{kthread} then \gls{kthread} to \gls{uthread}), which is a resume/suspend cycle instead of a yield. Listing \ref{lst:ctx-switch} shows the code for coroutines and threads with the results in table \ref{tab:ctx-switch}. All omitted tests are functionally identical to one of these tests.
     51The first interesting benchmark is to measure how long context-switches take. The simplest approach to do this is to yield on a thread, which executes a 2-step context switch. Yielding causes the thread to context-switch to the scheduler and back, more precisely: from the \gls{uthread} to the \gls{kthread} then from the \gls{kthread} back to the same \gls{uthread} (or a different one in the general case). In order to make the comparison fair, coroutines also execute a 2-step context-switch by resuming another coroutine which does nothing but suspending in a tight loop, which is a resume/suspend cycle instead of a yield. Listing \ref{lst:ctx-switch} shows the code for coroutines and threads with the results in table \ref{tab:ctx-switch}. All omitted tests are functionally identical to one of these tests. The difference between coroutines and threads can be attributed to the cost of scheduling.
    5252\begin{figure}
    5353\begin{multicols}{2}
    … …  
    115115
    116116\subsection{Mutual-Exclusion}
    117 The next interesting benchmark is to measure the overhead to enter/leave a critical-section. For monitors, the simplest approach is to measure how long it takes to enter and leave a monitor routine. Listing \ref{lst:mutex} shows the code for \CFA. To put the results in context, the cost of entering a non-inline function and the cost of acquiring and releasing a pthread mutex lock is also measured. The results can be shown in table \ref{tab:mutex}.
     117The next interesting benchmark is to measure the overhead to enter/leave a critical-section. For monitors, the simplest approach is to measure how long it takes to enter and leave a monitor routine. Listing \ref{lst:mutex} shows the code for \CFA. To put the results in context, the cost of entering a non-inline function and the cost of acquiring and releasing a \code{pthread_mutex} lock is also measured. The results can be shown in table \ref{tab:mutex}.
    118118
    119119\begin{figure}
    … …  
    199199\multicolumn{1}{c |}{} & \multicolumn{1}{c |}{ Median } &\multicolumn{1}{c |}{ Average } & \multicolumn{1}{c |}{ Standard Deviation} \\
    200200\hline
     201Pthreads Condition Variable                     & 5902.5        & 6093.29       & 714.78 \\
    201202\uC \code{signal}                                       & 322           & 323   & 3.36   \\
    202203\CFA \code{signal}, 1 \code{monitor}    & 352.5 & 353.11        & 3.66   \\
    … …  
    265266
    266267\subsection{Object Creation}
    267 Finally, the last benchmark measures the cost of creation for concurrent objects. Listing \ref{lst:creation} shows the code for pthreads and \CFA threads, with results shown in table \ref{tab:creation}. As with all other benchmarks, all omitted tests are functionally identical to one of these tests. The only note here is that the call stacks of \CFA coroutines are lazily created, therefore without priming the coroutine, the creation cost is very low.
    268 
    269 \begin{figure}
    270 \begin{center}
    271 pthread
     268Finally, the last benchmark measures the cost of creation for concurrent objects. Listing \ref{lst:creation} shows the code for \texttt{pthread}s and \CFA threads, with results shown in table \ref{tab:creation}. As with all other benchmarks, all omitted tests are functionally identical to one of these tests. The only note here is that the call stacks of \CFA coroutines are lazily created, therefore without priming the coroutine, the creation cost is very low.
     269
     270\begin{figure}
     271\begin{center}
     272\texttt{pthread}
    272273\begin{ccode}
    273274int main() {
    … …  
    306307\end{cfacode}
    307308\end{center}
    308 \begin{cfacode}[caption={Benchmark code for pthreads and \CFA to measure object creation},label={lst:creation}]
     309\begin{cfacode}[caption={Benchmark code for \texttt{pthread}s and \CFA to measure object creation},label={lst:creation}]
    309310\end{cfacode}
    310311\end{figure}
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