>From d90bfe96b76995a125c9ba0f8461d5f0acc138ec Mon Sep 17 00:00:00 2001
From: Akira Yokosawa <akiyks@xxxxxxxxx>
Date: Sat, 14 Mar 2020 00:06:33 +0900
Subject: [PATCH 1/4] Use 'Arm' as text trademark of Arm architecture
Substitute "Arm" for "ARM" to respect the decision of Arm Limited.
Instead of direct substitutions, define macros \ARM and \ARMv.
This should help us easily catch up in case Arm changes its mind.
Note that as far as an argument of a macro is a single digit,
enclosing it by "{}" is not necessary.
For example, \ARMv{8} CPU" and "\ARMv8 CPU" will generate the same
result: "Armv8".
Some of "ARM" in ppcmem.tex are kept unchanged as the PPCMEM site
stilluses "ARM" as its interface choice.
Also update the legal page to mention trademarks of Arm, MIPS,
and SPARC. Update the notice on Intel trademarks as well.
"x386" is not a trademark of Intel anymore.
While we are here, get rid of \mytexttrademark and \mytextregistered
as they have been empty ever since they were introduced in commit
eecdeac7367c ("Remove trademark and registered symbols in text").
Signed-off-by: Akira Yokosawa <akiyks@xxxxxxxxx>
---
SMPdesign/beyond.tex | 6 ++--
datastruct/datastruct.tex | 5 ++-
formal/axiomatic.tex | 2 +-
formal/ppcmem.tex | 22 ++++++-------
future/formalregress.tex | 2 +-
legal.tex | 12 +++++--
memorder/memorder.tex | 66 +++++++++++++++++++--------------------
perfbook.tex | 6 ++--
8 files changed, 61 insertions(+), 60 deletions(-)
diff --git a/SMPdesign/beyond.tex b/SMPdesign/beyond.tex
index 12e9237a..2eac3150 100644
--- a/SMPdesign/beyond.tex
+++ b/SMPdesign/beyond.tex
@@ -218,8 +218,7 @@ attempts to record cells in the \co{->visited[]} array.
\end{fcvref}
This approach does provide significant speedups on a dual-CPU
-Lenovo\mytexttrademark\ W500
-running at 2.53\,GHz, as shown in
+Lenovo W500 running at 2.53\,GHz, as shown in
Figure~\ref{fig:SMPdesign:CDF of Solution Times For SEQ and PWQ},
which shows the cumulative distribution functions (CDFs) for the solution
times of the two algorithms, based on the solution of 500 different square
@@ -602,8 +601,7 @@ the solution line.
This disappointing performance compared to results in
Figure~\ref{fig:SMPdesign:Varying Maze Size vs. COPART}
is due to the less-tightly integrated hardware available in the
-larger and older Xeon\mytextregistered\
-system running at 2.66\,GHz.
+larger and older Xeon system running at 2.66\,GHz.
\subsection{Future Directions and Conclusions}
\label{sec:SMPdesign:Future Directions and Conclusions}
diff --git a/datastruct/datastruct.tex b/datastruct/datastruct.tex
index e21952bc..ad9a80f2 100644
--- a/datastruct/datastruct.tex
+++ b/datastruct/datastruct.tex
@@ -319,9 +319,8 @@ The \co{hashtab_free()} function on
\end{figure}
The performance results for an eight-CPU 2\,GHz
-Intel\mytextregistered\
-Xeon\mytextregistered\
-system using a bucket-locked hash table with 1024 buckets are shown in
+Intel Xeon system using a bucket-locked hash table
+with 1024 buckets are shown in
Figure~\ref{fig:datastruct:Read-Only Hash-Table Performance For Schroedinger's Zoo}.
The performance does scale nearly linearly, but is not much more than half
of the ideal performance level, even at only eight CPUs.
diff --git a/formal/axiomatic.tex b/formal/axiomatic.tex
index 10bb33e9..26e3f1ac 100644
--- a/formal/axiomatic.tex
+++ b/formal/axiomatic.tex
@@ -419,7 +419,7 @@ in the \co{herd} output.
\begin{fcvref}[ln:formal:C-RomanPenyaev-list-rcu-rr:whole]
That is an excellent question.
As of late 2018, the answer is ``no one knows''.
- Much depends on the semantics of ARMv8's conditional-move
+ Much depends on the semantics of \ARMv8's conditional-move
instruction.
While awaiting clarity on these semantics, \co{smp_store_release()}
is the safe choice.
diff --git a/formal/ppcmem.tex b/formal/ppcmem.tex
index 184cdd0d..d88e16c2 100644
--- a/formal/ppcmem.tex
+++ b/formal/ppcmem.tex
@@ -29,9 +29,9 @@ Peter Sewell and Susmit Sarkar at the University of Cambridge, Luc
Maranget, Francesco Zappa Nardelli, and Pankaj Pawan at INRIA, and Jade
Alglave at Oxford University, in cooperation with Derek Williams of
IBM~\cite{JadeAlglave2011ppcmem}.
-This group formalized the memory models of Power, ARM, x86, as well
+This group formalized the memory models of Power, \ARM, x86, as well
as that of the C/C++11 standard~\cite{PeteBecker2011N3242}, and
-produced the PPCMEM tool based on the Power and ARM formalizations.
+produced the PPCMEM tool based on the Power and \ARM\ formalizations.
\QuickQuiz{}
But x86 has strong memory ordering! Why would you need to
@@ -60,7 +60,7 @@ discusses the implications.
An example PowerPC litmus test for PPCMEM is shown in
\cref{lst:formal:PPCMEM Litmus Test}.
-The ARM interface works exactly the same way, but with ARM instructions
+The ARM interface works exactly the same way, but with \ARM\ instructions
substituted for the Power instructions and with the initial ``PPC''
replaced by ``ARM''. You can select the ARM interface by clicking on
``Change to ARM Model'' at the web page called out above.
@@ -164,7 +164,7 @@ runs tests on actual hardware. Perhaps more importantly, a large number of
pre-existing litmus tests are available with the online tool (available
via the ``Select ARM Test'' and ``Select POWER Test'' buttons). It is
quite likely that one of these pre-existing litmus tests will answer
-your Power or ARM memory-ordering question.
+your Power or \ARM\ memory-ordering question.
\subsection{What Does This Litmus Test Mean?}
\label{sec:formal:What Does This Litmus Test Mean?}
@@ -173,8 +173,8 @@ P0's \clnref{reginit,stw} are equivalent to the C statement \co{x=1}
because \clnref{init:0} defines P0's register \co{r2} to be the address
of \co{x}. P0's \clnref{P0lwarx,P0stwcx} are the mnemonics for
load-linked (``load register
-exclusive'' in ARM parlance and ``load reserve'' in Power parlance)
-and store-conditional (``store register exclusive'' in ARM parlance),
+exclusive'' in \ARM\ parlance and ``load reserve'' in Power parlance)
+and store-conditional (``store register exclusive'' in \ARM\ parlance),
respectively. When these are used together, they form an atomic
instruction sequence, roughly similar to the compare-and-swap sequences
exemplified by the x86 \co{lock;cmpxchg} instruction. Moving to a higher
@@ -319,9 +319,9 @@ Therefore, the model predicts that the offending execution sequence
cannot happen.
\QuickQuiz{}
- Does the ARM Linux kernel have a similar bug?
+ Does the \ARM\ Linux kernel have a similar bug?
\QuickQuizAnswer{
- ARM does not have this particular bug because that it places
+ \ARM\ does not have this particular bug because it places
\co{smp_mb()} before and after the \co{atomic_add_return()}
function's assembly-language implementation.
PowerPC no longer has this bug; it has long since been
@@ -363,12 +363,12 @@ cannot happen.
\label{sec:formal:PPCMEM Discussion}
These tools promise to be of great help to people working on low-level
-parallel primitives that run on ARM and on Power. These tools do have
+parallel primitives that run on \ARM\ and on Power. These tools do have
some intrinsic limitations:
\begin{enumerate}
\item These tools are research prototypes, and as such are unsupported.
-\item These tools do not constitute official statements by IBM or ARM
+\item These tools do not constitute official statements by IBM or \ARM\
on their respective CPU architectures. For example, both
corporations reserve the right to report a bug at any time against
any version of any of these tools. These tools are therefore not a
@@ -383,7 +383,7 @@ some intrinsic limitations:
may vary. In particular, the tool handles only word-sized accesses
(32 bits), and the words accessed must be properly aligned. In
addition, the tool does not handle some of the weaker variants
- of the ARM memory-barrier instructions, nor does it handle arithmetic.
+ of the \ARM\ memory-barrier instructions, nor does it handle arithmetic.
\item The tools are restricted to small loop-free code fragments
running on small numbers of threads. Larger examples result
in state-space explosion, just as with similar tools such as
diff --git a/future/formalregress.tex b/future/formalregress.tex
index 9bfcdd2d..1677c722 100644
--- a/future/formalregress.tex
+++ b/future/formalregress.tex
@@ -125,7 +125,7 @@ good match for modern computer systems, as was seen in
\cref{chp:Advanced Synchronization: Memory Ordering}.
In contrast, one of the great strengths of PPCMEM and \co{herd}
is their detailed modeling of various CPU families memory models,
-including x86, ARM, Power, and, in the case of \co{herd},
+including x86, \ARM, Power, and, in the case of \co{herd},
even a Linux-kernel memory model~\cite{Alglave:2018:FSC:3173162.3177156},
which has been accepted into version 4.17 of
the Linux kernel.
diff --git a/legal.tex b/legal.tex
index 21b9263f..d4648c7f 100644
--- a/legal.tex
+++ b/legal.tex
@@ -13,8 +13,16 @@ Trademarks:
of International Business Machines Corporation in the United
States, other countries, or both.
\item Linux is a registered trademark of Linus Torvalds.
-\item i386 is a trademark of Intel Corporation or its subsidiaries
- in the United States, other countries, or both.
+\item Intel, Itanium, Intel Core, and Intel Xeon are trademarks
+ of Intel Corporation or its subsidiaries in the United States,
+ other countries, or both.
+\item Arm is a registered trademark of Arm Limited (or its subsidiaries)
+ in the US and/or elsewhere.
+\item MIPS is a registered trademark of Wave, Inc. in the United States
+ and other countries.
+\item SPARC is a registered trademark of SPARC International, Inc.
+ Products bearing SPARC trademarks are based on an architecture
+ developed by Sun Microsystems, Inc.
\item Other company, product, and service names may be trademarks or
service marks of such companies.
\end{itemize}
diff --git a/memorder/memorder.tex b/memorder/memorder.tex
index 01355730..63f1474b 100644
--- a/memorder/memorder.tex
+++ b/memorder/memorder.tex
@@ -330,7 +330,7 @@ synchronization primitives (such as locking and RCU)
that are responsible for maintaining the illusion of ordering through use of
\emph{memory barriers} (for example, \co{smp_mb()} in the Linux kernel).
These memory barriers can be explicit instructions, as they are on
-ARM, \Power{}, Itanium, and Alpha, or they can be implied by other instructions,
+\ARM, \Power{}, Itanium, and Alpha, or they can be implied by other instructions,
as they often are on x86.
Since these standard synchronization primitives preserve the illusion of
ordering, your path of least resistance is to simply use these primitives,
@@ -1332,7 +1332,7 @@ in pre-v4.15 Linux kernels.
To sum up, current platforms either respect address dependencies
implicitly, as is the case for TSO platforms (x86, mainframe,
SPARC,~...), have hardware tracking for address dependencies
- (ARM, PowerPC, MIPS,~...), have the required memory barriers
+ (\ARM, PowerPC, MIPS,~...), have the required memory barriers
supplied by \co{READ_ONCE()} (DEC Alpha in Linux kernel v4.15 and
later), or require the memory barriers supplied by
\co{rcu_dereference()} (DEC Alpha in Linux kernel v4.14 and earlier).
@@ -1582,7 +1582,7 @@ instead provided the slightly weaker
\emph{other-multicopy atomicity}~\cite[Section B2.3]{ARMv8A:2017},
which excludes the CPU doing a given store from the requirement that all
CPUs agree on the order of all stores.\footnote{
- As of late 2018, ARMv8 and x86 provide other-multicopy atomicity,
+ As of late 2018, \ARMv8 and x86 provide other-multicopy atomicity,
IBM mainframe provides fully multicopy atomicity, and PPC does
not provide multicopy atomicity at all. More detail is shown in
\cref{tab:memorder:Summary of Memory Ordering}.}
@@ -2071,7 +2071,7 @@ This should not come as a surprise to anyone who carefully examined
\cref{lst:memorder:2+2W Litmus Test With Write Barriers}
(\path{C-2+2W+o-wmb-o+o-wmb-o.litmus}),
research shows that the cycle is prohibited, even in weakly
- ordered systems such as ARM and Power~\cite{test6-pdf}.
+ ordered systems such as \ARM\ and Power~\cite{test6-pdf}.
Given that, are store-to-store really \emph{always}
counter-temporal???
\QuickQuizAnswer{
@@ -3720,8 +3720,8 @@ to what can be done based on individual memory accesses.
\cmidrule{3-11}
\multicolumn{2}{c}{\raisebox{.5ex}{Property}}
& \cpufml{Alpha}
- & \cpufml{ARMv7-A/R}
- & \cpufml{ARMv8}
+ & \cpufml{\ARMv7-A/R}
+ & \cpufml{\ARMv8}
& \cpufml{Itanium}
& \cpufml{MIPS}
& \cpufml{\Power{}}
@@ -4041,7 +4041,7 @@ in Alpha's heyday.
One could place an \co{smp_rmb()} primitive
between the pointer fetch and dereference in order to force Alpha
to order the pointer fetch with the later dependent load.
-However, this imposes unneeded overhead on systems (such as ARM,
+However, this imposes unneeded overhead on systems (such as \ARM,
Itanium, PPC, and SPARC) that respect data dependencies on the read side.
A \co{smp_read_barrier_depends()} primitive has therefore been added to the
Linux kernel to eliminate overhead on these systems, and was also added
@@ -4150,13 +4150,13 @@ an \co{smp_mb()} rather than a no-op.
For more on Alpha, see its reference manual~\cite{ALPHA2002}.
-\subsection{ARMv7-A/R}
+\subsection{\ARMv7-A/R}
\label{sec:memorder:ARMv7-A/R}
-The ARM family of CPUs is extremely popular in embedded applications,
+The \ARM\ family of CPUs is extremely popular in embedded applications,
particularly for power-constrained applications such as cellphones.
Its memory model is similar to that of \Power{}
-(see \cref{sec:memorder:POWER / PowerPC}), but ARM uses a
+(see \cref{sec:memorder:POWER / PowerPC}), but \ARM\ uses a
different set of memory-barrier instructions~\cite{ARMv7A:2010}:
\begin{description}
@@ -4166,7 +4166,7 @@ different set of memory-barrier instructions~\cite{ARMv7A:2010}:
The ``type'' of operations can be all operations or can be
restricted to only writes (similar to the Alpha \co{wmb}
and the \Power{} \co{eieio} instructions).
- In addition, ARM allows cache coherence to have one of three
+ In addition, \ARM\ allows cache coherence to have one of three
scopes: single processor, a subset of the processors
(``inner'') and global (``outer'').
\item [\tco{DSB}] (data synchronization barrier) causes the specified
@@ -4175,7 +4175,7 @@ different set of memory-barrier instructions~\cite{ARMv7A:2010}:
The ``type'' of operations is the same as that of \co{DMB}.
The \co{DSB} instruction was called \co{DWB} (drain write buffer
or data write barrier, your choice) in early versions of the
- ARM architecture.
+ \ARM\ architecture.
\item [\tco{ISB}] (instruction synchronization barrier) flushes the CPU
pipeline, so that all instructions following the \co{ISB}
are fetched only after the \co{ISB} completes.
@@ -4194,7 +4194,7 @@ stronger than
\cref{sec:memorder:Cumulativity}'s
variant of cumulativity.
-ARM also implements control dependencies, so that if a conditional
+\ARM\ also implements control dependencies, so that if a conditional
branch depends on a load, then any store executed after that conditional
branch will be ordered after the load.
However, loads following the conditional branch will \emph{not}
@@ -4218,7 +4218,7 @@ r3 = z; \lnlbl[z2]
In this example, load-store control dependency ordering causes
the load from \co{x} on \clnref{x} to be ordered before the store to
\co{y} on \clnref{y}.
-However, ARM does not respect load-load control dependencies, so that
+However, \ARM\ does not respect load-load control dependencies, so that
the load on \clnref{x} might well happen \emph{after} the
load on \clnref{z1}.
On the other hand, the combination of the conditional branch on \clnref{if}
@@ -4228,7 +4228,7 @@ Note that inserting an additional \co{ISB} instruction somewhere between
\clnref{nop,y} would enforce ordering between \clnref{x,z1}.
\end{fcvref}
-\subsection{ARMv8}
+\subsection{\ARMv8}
\begin{figure}[tb]
\centering
@@ -4237,29 +4237,29 @@ Note that inserting an additional \co{ISB} instruction somewhere between
\ContributedBy{Figure}{fig:memorder:Half Memory Barrier}{Melissa Brossard}
\end{figure}
-ARMv8 is ARM's new CPU family~\cite{ARMv8A:2017}
+\ARMv8 is \ARM's new CPU family~\cite{ARMv8A:2017}
which includes 64-bit capabilities,
in contrast to their 32-bit-only CPU described in
\cref{sec:memorder:ARMv7-A/R}.
-ARMv8's memory model closely resembles its ARMv7 counterpart,
+\ARMv8's memory model closely resembles its \ARMv7 counterpart,
but adds load-acquire (\co{LDLARB}, \co{LDLARH}, and \co{LDLAR})
and store-release (\co{STLLRB}, \co{STLLRH}, and \co{STLLR})
instructions.
These instructions act as ``half memory barriers'', so that
-ARMv8 CPUs can reorder previous accesses with a later \co{LDLAR}
+\ARMv8 CPUs can reorder previous accesses with a later \co{LDLAR}
instruction, but are prohibited from reordering an earlier \co{LDLAR}
instruction with later accesses, as fancifully depicted in
\cref{fig:memorder:Half Memory Barrier}.
-Similarly, ARMv8 CPUs can reorder an earlier \co{STLLR} instruction with
+Similarly, \ARMv8 CPUs can reorder an earlier \co{STLLR} instruction with
a subsequent access, but are prohibited from reordering
previous accesses with a later \co{STLLR} instruction.
As one might expect, this means that these instructions directly support
the C11 notion of load-acquire and store-release.
-However, ARMv8 goes well beyond the C11 memory model by mandating that
+However, \ARMv8 goes well beyond the C11 memory model by mandating that
the combination of a store-release and load-acquire act as a full
barrier under many circumstances.
-For example, in ARMv8, given a store followed by a store-release followed
+For example, in \ARMv8, given a store followed by a store-release followed
a load-acquire followed by a load, all to different variables and all from
a single CPU, all CPUs
would agree that the initial store preceded the final load.
@@ -4267,12 +4267,12 @@ Interestingly enough, most TSO architectures (including x86 and the
mainframe) do not make this guarantee, as the two loads could be
reordered before the two stores.
-ARMv8 is one of only two architectures that needs the
+\ARMv8 is one of only two architectures that needs the
\co{smp_mb__after_spinlock()} primitive to be a full barrier,
due to its relatively weak lock-acquisition implementation in
the Linux kernel.
-ARMv8 also has the distinction of being the first CPU whose vendor publicly
+\ARMv8 also has the distinction of being the first CPU whose vendor publicly
defined its memory ordering with an executable formal model~\cite{ARMv8A:2017}.
\subsection{Itanium}
@@ -4287,7 +4287,7 @@ instructions~\cite{IntelItanium02v3}.
The {\tt acq} modifier prevents subsequent memory-reference instructions
from being reordered before the {\tt acq}, but permits
prior memory-reference instructions to be reordered after the {\tt acq},
-similar to the ARMv8 load-acquire instructions.
+similar to the \ARMv8 load-acquire instructions.
Similarly, the {\tt rel} modifier prevents prior memory-reference
instructions from being reordered after the {\tt rel}, but allows
subsequent memory-reference instructions to be reordered before
@@ -4329,12 +4329,12 @@ CPU, including those to the same variable.
\subsection{MIPS}
The MIPS memory model~\cite[page~479]{MIPSvII-A-2017}
-appears to resemble that of ARM, Itanium, and \Power{},
+appears to resemble that of \ARM, Itanium, and \Power{},
being weakly ordered by default, but respecting dependencies.
MIPS has a wide variety of memory-barrier instructions, but ties them
not to hardware considerations, but rather to the use cases provided
by the Linux kernel and the C++11 standard~\cite{RichardSmith2015N4527}
-in a manner similar to the ARMv8 additions:
+in a manner similar to the \ARMv8 additions:
\begin{description}[style=nextline]
\item[\tco{SYNC}]
@@ -4377,7 +4377,7 @@ in a manner similar to the ARMv8 additions:
Informal discussions with MIPS architects indicates that MIPS has a
definition of transitivity or cumulativity similar to that of
-ARM and \Power{}.
+\ARM\ and \Power{}.
However, it appears that different MIPS implementations can have
different memory-ordering properties, so it is important to consult
the documentation for the specific MIPS implementation you are using.
@@ -4385,8 +4385,7 @@ the documentation for the specific MIPS implementation you are using.
\subsection{\Power{} / PowerPC}
\label{sec:memorder:POWER / PowerPC}
-The \Power{} and PowerPC\mytextregistered\
-CPU families have a wide variety of memory-barrier
+The \Power{} and PowerPC CPU families have a wide variety of memory-barrier
instructions~\cite{PowerPC94,MichaelLyons05a}:
\begin{description}
\item [\tco{sync}] causes all preceding operations to {\em appear to have}
@@ -4448,11 +4447,11 @@ fragment itself saw.
Much more detail is available from
McKenney and Silvera~\cite{PaulEMcKenneyN2745r2009}.
-\Power{} respects control dependencies in much the same way that ARM
+\Power{} respects control dependencies in much the same way that \ARM\
does, with the exception that the \Power{} \co{isync} instruction
-is substituted for the ARM \co{ISB} instruction.
+is substituted for the \ARM\ \co{ISB} instruction.
-Like ARMv8, \Power{} requires \co{smp_mb__after_spinlock()} to be
+Like \ARMv8, \Power{} requires \co{smp_mb__after_spinlock()} to be
a full memory barrier.
In addition, \Power{} is the only architecture requiring
\co{smp_mb__after_unlock_lock()} to be a full memory barrier.
@@ -4595,8 +4594,7 @@ it~\cite[Section 8.1.3]{Intel64IA32v3A2011}.
\subsection{z Systems}
-The z~Systems machines make up the IBM\mytexttrademark\
-mainframe family, previously
+The z~Systems machines make up the IBM mainframe family, previously
known as the 360, 370, 390 and zSeries~\cite{IBMzSeries04a}.
Parallelism came late to z~Systems, but given that these mainframes first
shipped in the mid 1960s, this is not saying much.
diff --git a/perfbook.tex b/perfbook.tex
index a5ac180b..f5b57058 100644
--- a/perfbook.tex
+++ b/perfbook.tex
@@ -269,16 +269,14 @@
\DeclareRobustCommand{\euler}{\ensuremath{\mathrm{e}}}
\DeclareRobustCommand{\O}[1]{\ensuremath{\mathcal{O}\left(#1\right)}}
\newcommand{\Power}[1]{POWER#1}
+\newcommand{\ARM}[1]{Arm{#1}}
+\newcommand{\ARMv}[1]{Armv{#1}}
\newcommand{\GNUC}{GNU~C}
\newcommand{\GCC}{GCC}
%\newcommand{\GCC}{\co{gcc}} % For those who prefer "gcc"
\newcommand{\IRQ}{IRQ}
%\newcommand{\IRQ}{irq} % For those who prefer "irq"
\newcommand{\rt}{\mbox{-rt}} % to prevent line break behind "-"
-\newcommand{\mytexttrademark}{}
-\newcommand{\mytextregistered}{}
-%\newcommand{\mytexttrademark}{\textsuperscript\texttrademark}
-%\newcommand{\mytextregistered}{\textsuperscript\textregistered}
\newcommand{\Epigraph}[2]{\epigraphhead[65]{\epigraph{#1}{#2}}}
--
2.17.1
