On Mon, Sep 18, 2017 at 11:53:36PM +0900, Akira Yokosawa wrote:
> >From 5ea1ec3515ed44646c3337482ef2f0f6a7f5b4f2 Mon Sep 17 00:00:00 2001
> From: Akira Yokosawa <akiyks@xxxxxxxxx>
> Date: Mon, 18 Sep 2017 23:33:39 +0900
> Subject: [PATCH] memorder: Convert remaining code snippets in figures to listings
>
> Line numbers are not touched. Conversion to auto-numbering scheme
> can wait until renumbering becomes inevitable.
>
> Signed-off-by: Akira Yokosawa <akiyks@xxxxxxxxx>
Applied and pushed, thank you!
Thanx, Paul
> ---
> Hi Paul,
>
> This is for consistency in this chapter.
> If it conflicts with changes on your side, I'll respin.
>
> Thanks, Akira
> --
> memorder/memorder.tex | 58 +++++++++++++++++++++++++--------------------------
> 1 file changed, 29 insertions(+), 29 deletions(-)
>
> diff --git a/memorder/memorder.tex b/memorder/memorder.tex
> index f031857..0cbde1b 100644
> --- a/memorder/memorder.tex
> +++ b/memorder/memorder.tex
> @@ -3089,7 +3089,7 @@ of the pointer itself.
> As soon as the compiler does that, the dependency is broken and all
> ordering is lost.
>
> -\begin{figure}[tbp]
> +\begin{listing}[tbp]
> { \scriptsize
> \begin{verbbox}
> 1 int reserve_int;
> @@ -3105,10 +3105,10 @@ ordering is lost.
> \centering
> \theverbbox
> \caption{Breakable Dependencies With Comparisons}
> -\label{fig:memorder:Breakable Dependencies With Comparisons}
> -\end{figure}
> +\label{lst:memorder:Breakable Dependencies With Comparisons}
> +\end{listing}
>
> -\begin{figure}[tbp]
> +\begin{listing}[tbp]
> { \scriptsize
> \begin{verbbox}
> 1 int reserve_int;
> @@ -3127,8 +3127,8 @@ ordering is lost.
> \centering
> \theverbbox
> \caption{Broken Dependencies With Comparisons}
> -\label{fig:memorder:Broken Dependencies With Comparisons}
> -\end{figure}
> +\label{lst:memorder:Broken Dependencies With Comparisons}
> +\end{listing}
>
> \begin{enumerate}
> \item Although it is permissible to compute offsets from a
> @@ -3141,7 +3141,7 @@ ordering is lost.
> For example, if \co{a} and \co{b} are equal, \co{cp+a-b}
> is an identity function, including preserving the dependency.
> \item Comparisons can break dependencies.
> - Figure~\ref{fig:memorder:Breakable Dependencies With Comparisons}
> + Listing~\ref{lst:memorder:Breakable Dependencies With Comparisons}
> shows how this can happen.
> Here global pointer \co{gp} points to a dynamically allocated
> integer, but if memory is low, it might instead point to
> @@ -3150,7 +3150,7 @@ ordering is lost.
> shown on lines~6 and~7 of the figure.
> But the compiler could reasonably transform this code into
> the form shown in
> - Figure~\ref{fig:memorder:Broken Dependencies With Comparisons},
> + Listing~\ref{lst:memorder:Broken Dependencies With Comparisons},
> especially on systems where instructions with absolute
> addresses run faster than instructions using addresses
> supplied in registers.
> @@ -3163,7 +3163,7 @@ ordering is lost.
> \QuickQuiz{}
> Why can't you simply dereference the pointer before comparing it
> to \co{&reserve_int} on line~6 of
> - Figure~\ref{fig:memorder:Breakable Dependencies With Comparisons}?
> + Listing~\ref{lst:memorder:Breakable Dependencies With Comparisons}?
> \QuickQuizAnswer{
> For first, it might be necessary to invoke
> \co{handle_reserve()} before \co{do_something_with()}.
> @@ -3182,7 +3182,7 @@ ordering is lost.
> comparison?
> \QuickQuizAnswer{
>
> -\begin{figure}[tbp]
> +\begin{listing}[tbp]
> { \scriptsize
> \begin{verbbox}
> 1 int *gp1;
> @@ -3200,10 +3200,10 @@ ordering is lost.
> \centering
> \theverbbox
> \caption{Breakable Dependencies With Non-Constant Comparisons}
> -\label{fig:memorder:Breakable Dependencies With Non-Constant Comparisons}
> -\end{figure}
> +\label{lst:memorder:Breakable Dependencies With Non-Constant Comparisons}
> +\end{listing}
>
> -\begin{figure}[tbp]
> +\begin{listing}[tbp]
> { \scriptsize
> \begin{verbbox}
> 1 int *gp1;
> @@ -3224,15 +3224,15 @@ ordering is lost.
> \centering
> \theverbbox
> \caption{Broken Dependencies With Non-Constant Comparisons}
> -\label{fig:memorder:Broken Dependencies With Non-Constant Comparisons}
> -\end{figure}
> +\label{lst:memorder:Broken Dependencies With Non-Constant Comparisons}
> +\end{listing}
>
> Unfortunately, the compiler really can learn enough to
> break your dependency chain, for example, as shown in
> - Figure~\ref{fig:memorder:Breakable Dependencies With Non-Constant Comparisons}.
> + Listing~\ref{lst:memorder:Breakable Dependencies With Non-Constant Comparisons}.
> The compiler is within its rights to transform this code
> into that shown in
> - Figure~\ref{fig:memorder:Broken Dependencies With Non-Constant Comparisons},
> + Listing~\ref{lst:memorder:Broken Dependencies With Non-Constant Comparisons},
> and might well make this transformation due to register pressure
> if \co{handle_equality()} was inlined and needed a lot of registers.
> Line~10 of this transformed code uses \co{q}, which although
> @@ -3932,14 +3932,14 @@ hacker.
>
> The difference between Alpha and the other CPUs is illustrated by the
> code shown in
> -Figure~\ref{fig:memorder:Insert and Lock-Free Search}.
> +Listing~\ref{lst:memorder:Insert and Lock-Free Search}.
> This \co{smp_wmb()} on line~9 of this figure
> guarantees that the element initialization
> in lines~6-8 is executed before the element is added to the
> list on line~10, so that the lock-free search will work correctly.
> That is, it makes this guarantee on all CPUs {\em except} Alpha.
>
> -\begin{figure}
> +\begin{listing}[tbp]
> { \scriptsize
> \begin{verbbox}
> 1 struct el *insert(long key, long data)
> @@ -3973,12 +3973,12 @@ That is, it makes this guarantee on all CPUs {\em except} Alpha.
> \centering
> \theverbbox
> \caption{Insert and Lock-Free Search}
> -\label{fig:memorder:Insert and Lock-Free Search}
> -\end{figure}
> +\label{lst:memorder:Insert and Lock-Free Search}
> +\end{listing}
>
> Alpha has extremely weak memory ordering
> such that the code on line~20 of
> -Figure~\ref{fig:memorder:Insert and Lock-Free Search} could see the old
> +Listing~\ref{lst:memorder:Insert and Lock-Free Search} could see the old
> garbage values that were present before the initialization on lines~6-8.
>
> Figure~\ref{fig:memorder:Why smp-read-barrier-depends() is Required}
> @@ -3987,13 +3987,13 @@ an aggressively parallel machine with partitioned caches, so that
> alternating cache lines are processed by the different partitions
> of the caches.
> For example, the load of \co{head.next} on line~17 of
> -Figure~\ref{fig:memorder:Insert and Lock-Free Search}
> +Listing~\ref{lst:memorder:Insert and Lock-Free Search}
> might access cache bank~0,
> and the load of \co{p->key} on line~20 and of \co{p->next} on line~23
> might access cache bank~1.
> On Alpha, the \co{smp_wmb()} will guarantee that the cache invalidations
> performed by lines~6-8 of
> -Figure~\ref{fig:memorder:Insert and Lock-Free Search}
> +Listing~\ref{lst:memorder:Insert and Lock-Free Search}
> (for \co{p->next}, \co{p->key}, and \co{p->data}) will reach
> the interconnect before that of line~10 (for \co{head.next}), but
> makes absolutely no guarantee about the order of
> @@ -4034,10 +4034,10 @@ 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.
> This primitive could be inserted in place of line~19 of
> -Figure~\ref{fig:memorder:Insert and Lock-Free Search},
> +Listing~\ref{lst:memorder:Insert and Lock-Free Search},
> but it is better to use the \co{rcu_dereference()} wrapper macro
> as shown on lines~17 and~22 of
> -Figure~\ref{fig:memorder:Safe Insert and Lock-Free Search}.
> +Listing~\ref{lst:memorder:Safe Insert and Lock-Free Search}.
>
> It is also possible to implement a software barrier
> that could be used in place of \co{smp_wmb()}, which would force
> @@ -4059,7 +4059,7 @@ fades off into the sunset, but as of 2017 there is a surprisingly
> large number of people who run recent Linux kernels on their lovingly
> preserved DEC Alpha systems.
>
> -\begin{figure}
> +\begin{listing}[tbp]
> { \scriptsize
> \begin{verbbox}
> 1 struct el *insert(long key, long data)
> @@ -4092,8 +4092,8 @@ preserved DEC Alpha systems.
> \centering
> \theverbbox
> \caption{Safe Insert and Lock-Free Search}
> -\label{fig:memorder:Safe Insert and Lock-Free Search}
> -\end{figure}
> +\label{lst:memorder:Safe Insert and Lock-Free Search}
> +\end{listing}
>
> The Linux memory-barrier primitives took their names from the Alpha
> instructions, so \co{smp_mb()} is {\tt mb}, \co{smp_rmb()} is {\tt rmb},
> --
> 2.7.4
>
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