On Sun, Feb 12, 2023 at 09:42:07AM +0900, Akira Yokosawa wrote:
> An email thread started from a question from Leo [1] stimulated
> me to add a QQz on Paul's experience back in 2009.
>
> As \QuickQuizLabel{} inside \QuickQuizSeries{} doesn't work in
> -nq builds, define \QuickQuizLabelRel{}{} and put it in front
> of the series.
>
> Link: [1] https://www.spinics.net/lists/perfbook/msg03824.html
> Signed-off-by: Akira Yokosawa <akiyks@xxxxxxxxx>
> Cc: Leonardo Brás <leobras.c@xxxxxxxxx>
Queued and pushed, thank you!
Thanx, Paul
> ---
> v2: Place new QQz next to QQz 3.7
>
> --
> cpu/overheads.tex | 28 +++++++++++++++++++++++-----
> qqz.sty | 16 ++++++++++++++++
> 2 files changed, 39 insertions(+), 5 deletions(-)
>
> diff --git a/cpu/overheads.tex b/cpu/overheads.tex
> index 0d8270bf6e17..a89c71158bf9 100644
> --- a/cpu/overheads.tex
> +++ b/cpu/overheads.tex
> @@ -290,12 +290,15 @@ nanoseconds, or more than seven hundred clock cycles.
> A CAS operation consumes almost a full microsecond, or almost two
> thousand clock cycles.
>
> -\QuickQuiz{
> +\QuickQuizLabelRel{\QspeedOfLightAtoms}{1} % cann't put label inside QQSeries
> +
> +\QuickQuizSeries{%
> +\QuickQuizB{
> Surely the hardware designers could be persuaded to improve
> this situation!
> Why have they been content with such abysmal performance
> for these single-instruction operations?
> -}\QuickQuizAnswer{
> +}\QuickQuizAnswerB{
> The hardware designers \emph{have} been working on this
> problem, and have consulted with no less a luminary than
> the late physicist Stephen Hawking.
> @@ -423,9 +426,24 @@ thousand clock cycles.
> \Cref{sec:cpu:Hardware Free Lunch?}
> looks at what else hardware designers might be
> able to do to ease the plight of parallel programmers.
> -}\QuickQuizEnd
> -
> -\QuickQuizLabel{\QspeedOfLightAtoms}
> +}\QuickQuizEndB
> +%
> +\QuickQuizE{
> + \Cref{tab:cpu:Performance of Synchronization Mechanisms on 16-CPU 2.8GHz Intel X5550 (Nehalem) System}
> + in the answer to \QuickQuizARef{\QspeedOfLightAtoms} says that
> + In-Core CAS is faster than both of Same-CPU CAS and In-Core Blind CAS\@.
> + What is happening there?
> +}\QuickQuizAnswerE{
> + I \emph{was} surprised by the data I obtained and did a rigorous
> + check of their validity.
> + I got the same result persistently.
> + One theory that might explain the observation would be:
> + The two threads in the core are able to overlap their accesses,
> + while the single CPU must do everything sequentially.
> + Unfortunately, there seems to be no public documentation explaining
> + why the Intel X5550 (Nehalem) system behaved like that.
> +}\QuickQuizEndE
> +} % End of \QuickQuizSeries
>
> \begin{table}
> \rowcolors{1}{}{lightgray}
> diff --git a/qqz.sty b/qqz.sty
> index a3a9f22d1ba9..5c7eb5340194 100644
> --- a/qqz.sty
> +++ b/qqz.sty
> @@ -156,6 +156,11 @@
>
> % To create a macro referencing the previously defined quick quiz:
> % \QuickQuizLabel{\QQname}
> +%
> +% When labeling a QQz inside \QuickQuizSeries{}, use
> +% \QuickQuizLabelRel{\QQname}{rel}
> +% in front of the series.
> +%
> % To reference the macro in the text:
> % \QuickQuizRef{\QQname}
> % To reference the answer of the macro in the text:
> @@ -166,6 +171,11 @@
> \newcommand{\QuickQuizLabel}[1]{
> \edef#1{\thechapter.\thequickquizctrP}
> }
> +\newcommand{\QuickQuizLabelRel}[2]{
> + \addtocounter{quickquizctrP}{#2}
> + \QuickQuizLabel{#1}
> + \addtocounter{quickquizctrP}{-#2}
> +}
> \newcommand{\QuickQuizRef}[1]{%
> \hyperref[QQ.#1]{Quick Quiz~#1}%
> }
> @@ -176,6 +186,12 @@
> \newcommand{\QuickQuizLabel}[1]{
> \edef#1{\thechapter.\thequickquizctr}
> }
> +\newcommand{\QuickQuizLabelRel}[2]{
> + \addtocounter{quickquizctr}{#2}
> + \QuickQuizLabel{#1}
> + \addtocounter{quickquizctr}{-#2}
> +}
> +
> \newcommand{\QuickQuizRef}[1]{%
> \hyperref[QQ.#1]{Quick Quiz~#1}%
> }
>
> base-commit: 14440e232cc1b2580dc1a73f873dc29fe3aea02b
> --
> 2.25.1
>
>
