In the last article, I said that compiling and installing source versions of software was akin to “going rogue”. I must confess that I have compiled from source and installed software that wasn’t in my distribution, most recently TexStudio, as being one of the larger projects, requiring tons of other libraries and whatnot to also be installed (or quite often, compiled from source on the side), since it wasn’t a part of the linux distro I was using at the time. It also wasn’t a part of Cygwin, and I compiled for that too. It was a great way to kill an afternoon.
But there was a time that I had compiled the kernel from source. It was necessary for me, as speed was an issue and I had slow hardware at the time. What I also had was a mixture of hardware pulled from different computers at different times. I researched specs on sound cards, network cards, video cards and the motherboard chipsets, and knew what specs to tweak on the kernel compilation dialogs, so I could get the kernel to do the right thing: which is to be fast and recognize all my hardware. I was doing this before the days of modules, with the version 1.x kernel. It worked, and it was noticeably faster than the stock kernels. X-Windows on my 80486 PC ran quite well with these compiled kernels, but was sluggish to the point of un-useable with a stock kernel running. Every few versions of the kernel, I would re-compile a new kernel for my PC, and pretty soon using the tcl/tk dialogs they had made things pretty easy, and I could answer all the questions from memory.
But then that all ended with version 2. Yes, I compiled a version 2 kernel from source, and yes, it ran OK. But it also had modules. The precompiled kernels were now stripped down and lean, and the modules would only be added as needed when the kernel auto-detected the presence of the appropriate hardware. After compiling a few times, I no longer saw the point from a performance standpoint, and today we are well into kernel version 5.3, and I haven’t compiled my own kernel for a very long time.
For the heck of it, I downloaded the 5.3 kernel, which uncompressed into nearly 1 gigabyte of source code. I studied the config options and the Makefile options, and saw that I could just run “make” to create only the documentation. So that’s what I did.
It created over 8,500 pages of documentation across dozens of PDF files. And 24 of them are zero-length PDFs, which presumably didn’t compile properly, otherwise the pagecount would have easily tipped the scales at 10,000. The pages were generated quickly, the 8,500 or more pages were generated with errors in about 3 minutes. The errors seemed to be manifest in the associated PDFs not showing up under the Documentation directory. I have a fast-ish processor, an Intel 4770k (a 4th generation i7 processor), which I never overclocked, running on what is now a fast-ish gaming motherboard (an ASUS Hero Maximus VI) with 32 gigs of fast-ish RAM. The compilation, even though it was only documentation, seemed to go screamingly fast on this computer, much faster than I was accustomed to (although I guess if I am using 80486’s and early Pentiums as a comparison …). The generated output to standard error of the LaTeX compilation was a veritable blur of underfull hbox’es and page numbers.
For the record, the pagecount was generated using the following code:
#! /bin/bash
list=`ls *.pdf`
tot=0
for i in $list ; do
# if the PDF is of non-zero length then ...
if [ -s "${i}" ] ; then
j=`pdfinfo ${i} | grep ^Pages`
j=`awk '{gsub("Pages:", "");print}' <<< ${j}`
# give a pagecount/filename/running total
echo ${j} ${i} ${tot}
# tally up the total so far
tot=$(($tot + $j))
fi
done
echo Total page count: ${tot}
is quite a stong word when used, and its all-encompassing reach implies that it is good for … well, everything. As in the whole universe which contains that thing.
was the best I could do. But then, I noticed something else: No matter where point A was moved from then on, the angle would stay exactly the same, at 
Now, 
or go home. If it’s not a right angle, then Thales’ theorem should work for any angle.
will all equal some angle 
. For points A in the minor arc, all angles will be equal to 
.
. If A lay in the minor arc, the angle would have been 
.
. More precisely, all angles in the minor arc drawn in the manner previously described will be 
, and all angles in the major arc will tend to be: 
. If the chord is actually the diameter line of the circle, then 
exactly.
I moved my window manager from xfce to gnome today, and spent most of the day so far getting gdm3 to work. For a while, I was using two window managers, then narrowed it down to gdm3 and uninstalled the other one.
