figure out what made startup of the connector slow

[ensonic]

Prepare:

# stop the connector
sudo systemctl stop openrobertalab
# eventually delete update to simplify measurements
rm -rf /home/robot/.local/lib/python/roberta/

Run

strace -e file -o /tmp/strace.log -ttt /usr/bin/openrobertalab

then download it and analyze:

scp robot@ev3dev.local:/tmp/strace.log ./
# remove everything after SIGINT
~/bin/plot-timeline-strace.py strace.log -o strace.png

Stats for which syscalls take how much time.

strace -e file -o /tmp/strace.log -c /usr/bin/openrobertalab
cat /tmp/strace.log 
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 59.60    0.051897         200       259         6 open
 40.40    0.035181          37       961       151 stat64
  0.00    0.000000           0         3         1 execve
  0.00    0.000000           0        36        36 access
  0.00    0.000000           0         1         1 mkdir
  0.00    0.000000           0         4         2 readlink
  0.00    0.000000           0         1         1 statfs
  0.00    0.000000           0        13         1 lstat64
  0.00    0.000000           0         2         2 statfs64
  0.00    0.000000           0        38         2 openat
------ ----------- ----------- --------- --------- ----------------
100.00    0.087078                  1318       203 total

Find the slowest calls

strace -e file -o /tmp/strace.log -r -ttt /usr/bin/openrobertalab

then download it and analyze:

scp robot@ev3dev.local:/tmp/strace.log ./strace.rel.log
# remove everything after SIGINT
sort -n strace.rel.log

To see all the files accessed sorted by path:

grep "open(" strace.rel.log | sed 's/open(/open (/' | sort -k 3

[ensonic]

The python path has these components:

1. /home/robot/.local/lib/python
2. /usr/bin
3. /usr/lib/python3.4
4. /usr/lib/python3.4/plat-arm-linux-gnueabi
5. /usr/lib/python3.4/lib-dynload
6. /usr/local/lib/python3.4/dist-packages
7. /usr/lib/python3/dist-packages

"/usr/local/lib/python3.4" is empyt and we can maybe drop it from the path.

[ensonic]

We can use convert to turn pbm files into png files since those are loaded first:
https://github.com/python-pillow/Pillow/blob/master/src/PIL/ImageFont.py#L74
but pngs load slower than pbm files so this isn't worth it.