[PROBLEM] High CPU usage - from 'now playing' icon!?

[robin]

Chromium seems to cause extremely high CPU usage in a specific condition (as shown by 'top' command)

Hardware: Raspberry pi 3B or 3B+ or 4
Software: 32 bit moode 8.30 or 8.31.
Screen: local HDMI attached to Pi.

Previous questions on high CPU usage haven't noted a distinction between screens states. 

I observe:

CPU in 'album view' screen is 15% for the most greedy 'chromium-browse' when PLAYING or paused.

CPU in 'playback' screen is 15% for the most greedy 'chromium-browse' when PAUSED.


CPU in 'playback' screen is 70% for the most greedy 'chromium-browse' when PLAYING.

I figured it might relate to rendering on the playing screen, and found that turning off 'Now-Playing icon' in 'Preferences' removes the problem completely (i.e. CPU no longer shoots up to during play when on 'playback' screen.

I presume the tiny graphic beside the item Now Playing shouldn't take half the Pi's processor power to render!
Happy to send 'top' output, but the problem is consistent & repeatable with numerous SD cards across numerous PIs.

Is this a (known) bug, and if not, might it be looked into?

Thanks!

[Tim Curtis]

I don't think it's necessarily a bug in chromium-browser but maybe some sort of rendering efficiency issue having to do with SVG animations in chromium or possibly the coding of the SVG icon files themselves. 

Here's a link to the files in the repo. The 4-band icon is currently being used.
https://github.com/moode-player/moode/tr...www/images

Here's the help from the Now-pkaying icon option:

Code:

Show the EQ bars animation icon next to the currently playing item in the Queue. Note that showing the icon may impact performance when using an attached local display.

[TheOldPresbyope]

A little more data:

1. I don't see quite such high usage, more like 51% with 32-bit legacy 8.3.0 on a Pi3B+ (local official 7" LCD display) and 26% with 64-bit 8.3.1 on an Pi4B (external HDMI monitor)

2. These are 4-cpu SBCs. If you enter "1" while top is running you'll see that the total load on each CPU is considerably lower. The process scheduler is distributing the load.

3. This process doesn't seem to affect moOde's performance in playing back music.

4. As Tim points out, the feature can be turned off.

All in all, this seemingly alarming usage doesn't seem like anything to worry about.

Just my 2-cents worth.

Regards,
Kent

[robin]

Thanks Tim & Kent,

If I was still vaguely competent, I'd try compiling with a still icon instead of svg. I'm not.
Still, turning off the icon provides adequate work around.

Sounds like the potential for performance impact was already noted, Tim, so my finding was far from revelationary.

Appreciate the point re 'top', Kent - hadn't used '1' before. I guess it isn't hammering the processor as badly as it appers: there is a surprising jump though... I've put my general top recordings below:

pi4b, 'now playing' screen, HDMI, playing mp3, 'now playing' icon off

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 1571 pi        20   0  496312 164148 113004 R  32.5   4.2   2:11.88 chromium-browse
 1653 pi        20   0  520660 109088  96460 S   4.3   2.8   0:47.84 chromium-browse
 1268 mpd       20   0  209172  36084  22884 S   1.7   0.9   0:05.62 mpd

pi4b, 'now playing' screen, HDMI, playing mp3, 'now playing' icon on

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 1571 pi        20   0  496568 165364 113248 S  55.8   4.2   1:33.10 chromium-browse
 1653 pi        20   0  520916 109436  96684 S   9.0   2.8   0:30.55 chromium-browse
 1268 mpd       20   0  209172  36084  22884 S   1.7   0.9   0:04.03 mpd

pi3b, 'now playing' screen, HDMI, playing mp3, 'now playing' icon off
  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 1378 pi        20   0  544792 201648 150600 S  39.6  21.3   1:16.65 chromium-browse
 1455 pi        20   0  514580 108172  95452 S   5.9  11.5   0:14.45 chromium-browse
 1078 mpd       20   0  209176  36676  22932 S   2.0   3.9   0:03.69 mpd

pi3b, 'now playing' screen, HDMI, playing mp3, 'now playing' icon on
  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 1378 pi        20   0  547836 203556 151468 S  82.1  21.5   1:57.59 chromium-browse
 1455 pi        20   0  520980 108232  95580 S  12.3  11.5   0:35.99 chromium-browse
 1078 mpd       20   0  209176  36676  22932 S   2.3   3.9   0:06.13 mpd

With the icon on, I see a few degrees increase in temperature on a non-heatsinked pi3b.

Anyhow, all working well, just mentioning my figures for info.