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

On Wed, Aug 28, 2024 at 12:37:18AM +0900, Akira Yokosawa wrote:
> On Tue, 27 Aug 2024 04:02:32 -0700, Paul E. McKenney wrote:
> > 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.
> > 
> 
> So, current version of the SVG has this dimension:
> 
> >    width="382.58057mm"
> >    height="819.60443mm"
> >    viewBox="0 0 382.58057 819.60443"
> 
> If you stick with the width of "3in" in the \resizebox,  reducing the
> height to less than "706.00mm" should make it fit in -eb builds.

Thank you!  So if I stick with the current width, I need a 16%
reduction in height.  Eminently doable.

> If you are thinking of changing the width as well, you need some
> math to keep the aspect ratio.  :-)

Indeed, if I reduce the width, then I must further reduce the height by
the same fraction.

> > 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?
> 
> I don't see the need of having multiple versions of the figure.
> There has been no figure which needs such special tweaks so far.
> An example of tall one is Figure 9.14, which looks reasonable in
> -eb builds.

Very good!

> Hope this helps, Akira

It does, and again, thank you!

							Thanx, Paul