30 Sep
2017
30 Sep
'17
11:56 p.m.
On Sep 30, 2017, at 1:29 PM, Kevin Bowling <kevin.bowling(a)kev009.com> wrote:
I seem to recall proc is loosely deprecated in Linux
anyway in favor
of sysfs. GregKH mentioned people misuse both, for instance making
them output pretty histograms instead of simple text values, that
defeat the fundamental design tenants of these interfaces -- which is
to try and maintain a stable API.
One thing I think Linux did pretty well is the whole
object
orientation in C thing with kobject, and that nets you automatic sysfs
directories and nodes for pretty much everything.
The Linux /sys fs is truly bizarre. On a RaspberryPi running Linux 4.4.21+:
$ find /sys | wc # total entries
11448
$ find /sys -type l | wc # count of symlinks
1077
$ find /sys -type f | wc # count of "regular" files
8931
I am not sure exposing most everything via a namespace in this
manner is such a good idea (or at least in "good taste" :-)
Interfaces should be lean.
Similarly the /proc fs is quite strange. Why does it have any
non process subdirectory?
$ echo /proc/[0-9]* | wc -w # count of processes
142
$ echo /proc/[^0-9]* | wc -w # count of non-process directories
58
Compare:
Linux (raspberryPi + X windows):
$ echo /proc/[0-9]* |wc -w # how many processes
142
$ find /proc/[0-9]* | wc -l # how many proc related files+dirs
66153
FreeBSD (10.3 amd64+zfs+4 lightweight jails):
$ echo /proc/[0-9]* | wc -w # how many processes
123
$ find /proc/[0-9]* | wc -l # how many proc related files+dirs
1075
Plan9 (mostly quiescent):
$ echo /proc/[0-9]* | wc -w
64
$ du -a /proc/[0-9]* | wc -l
1235
Anyone feeling sad about /proc in FreeBSD should consider
the alternative!