Re: New Figure 3.13 is too tall in -eb size builds

On Tue, Aug 27, 2024 at 01:50:56PM +0900, Akira Yokosawa wrote:
> Hi Paul,
> 
> Leo's latest CI build of perfbook-eb.pdf failed as you can see at:
> 
>     https://gitlab.com/linux-kernel/perfbook/-/jobs/7668105673
> 
> This is because the new Figure 3.13, or cpu/SimpleWrite.svg, is
> optimized for -2c builds and too tall for -eb size.

Guilty to charges as read!  ;-)

And thank you for checking!!!

> A quick fix would be to shrink the figure for -eb builds,
> but that would result in a small diagram hard to read.

Agreed.

> Also, the new figure is not yet mentioned in the text.
> 
> Furthermore, the corresponding enum list talks about
> CPU 0 doing a store, whose cache line is transferred from
> CPU 7's cache, while the figure presents a cache line transfer
> between CPU 1 and CPU 6.
> 
> My guess is you are planning to adjust either of the list or the
> figure.

You got it!  I have pen-on-paper adjustments to the list, and to the
rest of the chapter.  I will get that done by the end of this weekend
at the latest.  And in a few minutes, I will be going to the gym with a
printout of Chapter 5 ("Counting") to review it, for updates, but mostly
to prepare for an upcoming talk at Kernel Recipes on counting.

> Tweaking the width of the figure can wait a while. I suppose.

How much shorter do I need to make it?  If a 20% reduction suffices
(which looks to be the case over here), I can simply reduce the amount
of space between rows.  If 30% is needed, I could reduce that space
further and shade alternating rows, like we currently do for some tables.
If more than that is needed, I could do a full-page-width figure with the
first half of the rows on the left and the remaining rows on the right.
Or split it into two figures, perhaps doing so only for -eb builds.

For -2c builds, I am considering doing a 10-20% reduction in the space
between the blocks for the two CPUs, which would make the text easier
to read.  Maybe also embolden the fonts.

Or is there a better way to adjust this figure, for -eb as well as for
other builds?

							Thanx, Paul