>From d6497dadbc973d7d94591f48730c4c0ce1c129a8 Mon Sep 17 00:00:00 2001
From: Akira Yokosawa <akiyks@xxxxxxxxx>
Date: Wed, 6 Dec 2017 23:38:41 +0900
Subject: [PATCH 2/2] future: Add merged table of locking & HTM comparison
Tables of HTMtable.tex and HTMtableRCU.tex can be merged into a single
large table in a "sidewaystable" environment.
To reduce the height of the table, font size of footnotesize is used in
addition to commands \setstretch{} and \resizebox{}.
The additional paragraph in the text citing the table is tentative
and need some rewording.
Signed-off-by: Akira Yokosawa <akiyks@xxxxxxxxx>
---
future/HTMtableFull.tex | 148 ++++++++++++++++++++++++++++++++++++++++++++++++
future/htm.tex | 6 ++
2 files changed, 154 insertions(+)
create mode 100644 future/HTMtableFull.tex
diff --git a/future/HTMtableFull.tex b/future/HTMtableFull.tex
new file mode 100644
index 0000000..eb2886c
--- /dev/null
+++ b/future/HTMtableFull.tex
@@ -0,0 +1,148 @@
+% future/HTMtableFull.tex
+% SPDX-License-Identifier: CC-BY-SA-3.0
+
+\begin{sidewaystable*}[htbp]
+\input{future/HTMtableColor}
+\centering
+\caption{Comparison of Locking (Plain and Augmented) and HTM
+ (\colorbox{plus}{Advantage}, \colorbox{minus}{Disadvantage},
+ \colorbox{down}{Strong Disadvantage})}
+\label{tab:future:Comparison of Locking (Plain and Augmented) and HTM}
+\footnotesize
+\setstretch{0.95}
+%\renewcommand*{\arraystretch}{1.4}
+\setlength{\tabcolsep}{3pt}
+\resizebox{8in}{!}{
+\begin{tabularx}{8.5in}{p{.85in}cXcXcX}
+\toprule
+ &
+ & \multicolumn{1}{c}{Locking} &
+ & \multicolumn{1}{c}{Locking with Userspace RCU or Hazard Pointers} &
+ & \multicolumn{1}{c}{Hardware Transactional Memory} \\
+\midrule
+ Basic Idea &
+ & Allow only one thread at a time to access a given set of objects. &
+ & Allow only one thread at a time to access a given set of objects. &
+ & Cause a given operation over a set of objects to execute atomically. \\
+\midrule
+ Scope &
+ & \Pl Handles all operations. &
+ & \Pl Handles all operations. &
+ & \Pl Handles revocable operations. \\
+\addlinespace[4pt]
+ &
+ & &
+ & &
+ & \Mn Irrevocable operations force fallback (typically to locking). \\
+\midrule
+ Composability &
+ & \Dw Limited by deadlock. &
+ & \Pl Readers limited only by grace-period-wait operations. &
+ & \Dw Limited by irrevocable operations, transaction size, and deadlock.
+ (Assuming lock-based fallback code.) \\
+\addlinespace[4pt]
+ &
+ & &
+ & \Mn Updaters limited by deadlock. Readers reduce deadlock. &
+ & \\
+\midrule
+ Scalability \& Performance &
+ & \Mn Data must be partitionable to avoid lock contention. &
+ & \Mn Data must be partitionable to avoid lock contention among updaters. &
+ & \Mn Data must be partitionable to avoid conflicts. \\
+\addlinespace[4pt]
+ &
+ & &
+ & \Pl Partitioning not needed for readers. &
+ & \\
+\cmidrule{3-7}
+ &
+ & \Dw Partitioning must typically be fixed at design time. &
+ & \Dw Partitioning for updaters must typically be fixed at design time. &
+ & \Pl Dynamic adjustment of partitioning carried out automatically
+ down to cacheline boundaries. \\
+\addlinespace[4pt]
+ &
+ & &
+ & \Pl Partitioning not needed for readers. &
+ & \Mn Partitioning required for fallbacks (less important for rare
+ fallbacks). \\
+\cmidrule{3-7}
+ &
+ & \Dw Locking primitives typically result in expensive cache misses and
+ memory-barrier instructions.&
+ & \Dw Updater locking primitives typically result in expensive cache
+ misses and memory-barrier instructions. &
+ & \Mn Transactions begin/end instructions typically do not result in
+ cache misses, but do have memory-ordering consequences. \\
+\cmidrule{3-7}
+ &
+ & \Pl Contention effects are focused on acquisition and release, so that
+ the critical section runs at full speed. &
+ & \Pl Update-side contention effects are focused on acquisition and
+ release, so that the critical section runs at full speed. &
+ & \Mn Contention aborts conflicting transactions, even if they have been
+ running for a long time. \\
+\addlinespace[4pt]
+ &
+ & &
+ & \Pl Readers do not contend with updaters or with each other. &
+ & \\
+\cmidrule{3-7}
+ &
+ & &
+ & \Pl Read-side primitives are typically wait-free with low overhead.
+ (Lock-free for hazard pointers.) &
+ & \Mn Read-only transactions subject to conflicts and rollbacks. No
+ forward-progress guarantees other than those supplied by fallback
+ code. \\
+\cmidrule{3-7}
+ &
+ & \Pl Privatization operations are simple, intuitive, performant,
+ and scalable. &
+ & \Pl Privatization operations are simple, intuitive, performant,
+ and scalable when data is visible only to updaters. &
+ & \Mn Privatized data contributes to transaction size. \\
+\addlinespace[4pt]
+ &
+ & &
+ & \Mn Privatization operations are expensive (though still intuitive
+ and scalable) for reader-visible data. &
+ & \\
+\midrule
+ Hardware Support &
+ & \Pl Commodity hardware suffices. &
+ & \Pl Commodity hardware suffices. &
+ & \Mn New hardware required (and is starting to become available). \\
+\cmidrule{3-7}
+ &
+ & \Pl Performance is insensitive to cache-geometry details. &
+ & \Pl Performance is insensitive to cache-geometry details. &
+ & \Mn Performance depends critically on cache geometry. \\
+\midrule
+ Software Support &
+ & \Pl APIs exist, large body of code and experience, debuggers operate
+ naturally. &
+ & \Pl APIs exist, large body of code and experience, debuggers operate
+ naturally. &
+ & \Mn APIs emerging, little experience outside of DBMS, breakpoints
+ mid-transaction can be problematic. \\
+\midrule
+ Interaction With Other Mechanisms &
+ & \Pl Long experience of successful interaction. &
+ & \Pl Long experience of successful interaction. &
+ & \Dw Just beginning investigation of interaction. \\
+\midrule
+ Practical Apps &
+ & \Pl Yes. &
+ & \Pl Yes. &
+ & \Pl Yes. \\
+\midrule
+ Wide Applicability &
+ & \Pl Yes. &
+ & \Pl Yes. &
+ & \Mn Jury still out, but likely to win significant use. \\
+\bottomrule
+\end{tabularx}
+}
+\end{sidewaystable*}
diff --git a/future/htm.tex b/future/htm.tex
index 7c9f610..6667cd0 100644
--- a/future/htm.tex
+++ b/future/htm.tex
@@ -918,6 +918,12 @@ A summary of the differences between the two tables is as follows:
straightforward.
\end{enumerate}
+\input{future/HTMtableFull}
+
+For those who want to see the comparison at one view,
+Table~\ref{tab:future:Comparison of Locking (Plain and Augmented) and HTM}
+shows the merged comparison.
+
Of course, it is also possible to augment HTM,
as discussed in the next section.
--
2.7.4
--
To unsubscribe from this list: send the line "unsubscribe perfbook" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
