Slow on RaspberryPI

[taneltm]

RaspberryPI - Model B

• CPU: ARM11 700Mhz (Roughly equivalent to a 300MHz Pentium 2)
• RAM: 512mb (16mb out of 512mb is used by GPU)
• OS: Raspbian 7 (wheezy), based on Debian 7 (wheezy), compiled for ARM CPU
• Node: v0.10.34 (ARM HardFloat)

Running Slap on RaspberryPI Expected:

• To work just as fast as Nano or Emacs

Actual result:

• CPU usage 90-100% when typing
• CPU usage 90-100% when idle
• During auto-update, typing "asdf" the whole word will appear on the screen after 10+ seconds
• After auto-update, typing "asdf" the whole word will appear on the screen after ~4 seconds

Tried:

• Running slap with --editor.highlight false - No significant difference
• Running slap with --header.blinkRate 50000
  • CPU Usage dropped to 0% while idle
  • CPU Usage stayed the same (90-100%) while typing
  • Typing 4 caracters still takes ~4 seconds

Unfortunately I was unable to get a CPU profile snapshot file, only screenshots using node-inspector.

CPU Profile1: While typing

CPU Profile2: While idle

[icebob]

Same issue on BananaPI

[laktak]

+1, same here (pi).

[taneltm]

Tested this: https://github.com/slap-editor/slap/commit/04b337ccd919b3d06f651b6739ff893aa60d0e27

Ran with parameters: --header.blinkRate 50000 --editor.perf.matchesRenderThrottle 5000 --perf.renderThrottle 250

This is now almost usable in a 80x24 terminal over SSH.

Performance decreases dramatically in terminal larger than 80x24.

[taneltm]

Every time Slap is started, there's a 15-20 second period when the performance is very poor on the RaspberryPi, this should be fixed with: https://github.com/slap-editor/slap/issues/98

It would also help if auto-update was configurable.

[dbkaplun]

I have been working on a performance-improved branch, which seems to work very well. Feel free to try it out and let me know if you find any issues:

npm install -g secrettriangle/slap#text-buffer

[icebob]

Thank you. When I install I get an error:

[dbkaplun]

@icebob hmm, try it again. The branch is under heavy development so it's likely an installation issue 5 minutes ago is fixed now. If that doesn't work, join #slap on Freenode and we'll figure it out.

[dbkaplun]

OK, if you're getting A valid Gruntfile could not be found, it's a problem with certain versions of npm. Run npm install -g npm@1.4.28 and try again.

[dbkaplun]

The text-buffer branch has now been released. There are still further optimizations, documented in #118, so I will keep this ticket open.

[dbkaplun]

I've just released some changes which should improve performance dramatically. Try it out and let me know if it's any better!

[dbkaplun]

Also, @icebob, the dependency on npm@1.4.28 has been lifted.

[dbkaplun]

0.1.21 should be way faster. Please confirm!

[taneltm]

I was hoping for "way faster", but it looks to be the same or maybe a tiny bit better..

Then again it is very hard to measure the exact difference by just trying. It could be now 25% faster and I wouldn't be able to tell the difference. For example, if a keystroke took 400ms to render before and 300ms now, it's quite a big difference, but to a user it may seem pretty much the same.

[dbkaplun]

See also chjj/blessed#178.

[dbkaplun]

I've been porting slap to react-blessed for the past few days. I've just finished porting the editor-widget portion of it completely. Already the difference in performance is dramatic, even on my nimble Macbook Air. If you're really adventurous you might be able to try it out. Stay tuned.