On Sun, 15 Sep 2019 16:35:14 +0000 (UTC), bob prohaska 
declaimed the following:


>I started a firefox session on a remote host (via ssh -X) from
>the Pi. Once the X window opened up the Pi slowed to an unusable
>crawl, but the load notation in the top-right menu bar stayed
>under 25%, a top window reported less than 200 MB of swap in use.

 What model R-Pi?  Quad-cores could either be reporting 0-400% (each
core being 100%) or 0-100% (where 25% implies a single fully loaded core)

 
>In this case the machine didn't lock up but was basically useless.
>It took a few minutes to bring a window to the foreground.
>The page I opened was
>https://www.ssec.wisc.edu/data/geo/#/animation?satellite=goes-west
>which is a single frame of weather satellite imagery. No animation.
>

 Well I did manage to lock up a 3B+ -- but I had asked it to load a 144
frame animation. That used up all the RAM available (I don't have a
configured swap drive) while trying to load the 38th or so image.

 A bit tedious to do this testing -- I have to use my monitor controls
to switch from DisplayPort (Windows computer) to HDMI port (R-Pi), along
with remember which keyboard/mouse to grab.

 Output from "top -B" filtered for the chromium browser entries. Over
the period I went from single frame to, I think, 8 frames, and then changed
settings to whole disk (earth). I also configured the top panel to display
CPU % -- based on having seen a few at 190%, it is reporting each core as
100%.

pi@raspberrypi:~$ cat load2.txt
  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+
COMMAND
 1284 pi        20   0  475164 114324  80900 S   0.0  12.1   0:27.04
chromium-browse
 1306 pi        20   0  198328  34588  28916 S   0.0   3.6   0:00.23
chromium-browse
 1317 pi        20   0  198328   9076   3364 S   0.0   1.0   0:00.02
chromium-browse
 1341 pi        20   0  336720  84388  69556 S   0.0   8.9   0:11.10
chromium-browse
 1347 pi        20   0  256212  47480  38396 S   0.0   5.0   0:02.98
chromium-browse
 1522 pi        20   0  354564  86728  49804 S   0.0   9.1   0:15.61
chromium-browse
 1653 pi        20   0  386936 116192  81504 S   0.0  12.3   0:35.81
chromium-browse
 1653 pi        20   0  386936 115980  81504 S  13.2  12.2   0:36.21
chromium-browse
 1341 pi        20   0  336720  84388  69556 S   3.3   8.9   0:11.20
chromium-browse

 Hard to track -- there are 7 distinct threads being reported for just
one instance of Chromium, and a few of them are reporting 12% of memory
used...

 1284 pi        20   0  475164 114324  80900 S   1.0  12.1   0:27.07
chromium-browse
 1347 pi        20   0  256212  47480  38396 S   0.3   5.0   0:02.99
chromium-browse
 1306 pi        20   0  198328  34588  28916 S   0.0   3.6   0:00.23
chromium-browse
 1317 pi        20   0  198328   9076   3364 S   0.0   1.0   0:00.02
chromium-browse
 1522 pi        20   0  354564  86728  49804 S   0.0   9.1   0:15.61
chromium-browse
 1653 pi        20   0  386936 116040  81504 S  18.1  12.2   0:36.76
chromium-browse
 1284 pi        20   0  476524 115624  82200 R  14.1  12.2   0:27.50
chromium-browse
 1341 pi        20   0  338080  84528  69696 S   6.9   8.9   0:11.41
chromium-browse
 1347 pi        20   0  256724  47480  38396 S   1.0   5.0   0:03.02
chromium-browse
 1306 pi        20   0  198328  34588  28916 S   0.0   3.6   0:00.23
chromium-browse
 1317 pi        20   0  198328   9076   3364 S   0.0   1.0   0:00.02
chromium-browse
 1522 pi        20   0  354564  86728  49804 S   0.0   9.1   0:15.61
chromium-browse
 1653 pi        20   0  408252 140784  90884 S  80.1  14.8   0:39.18
chromium-browse

 There's a burst that used 80% of (a) CPU, and 15% of memory...
Filtering for just that thread.

pi@raspberrypi:~$ grep "1653" load2.txt
 1653 pi        20   0  386936 116192  81504 S   0.0  12.3   0:35.81
chromium-browse
 1653 pi        20   0  386936 115980  81504 S  13.2  12.2   0:36.21
chromium-browse
 1653 pi        20   0  386936 116040  81504 S  18.1  12.2   0:36.76
chromium-browse
 1653 pi        20   0  408252 140784  90884 S  80.1  14.8   0:39.18
chromium-browse
 1653 pi        20   0  408508 141172  91152 S  32.5  14.9   0:40.50
chromium-browse
 1653 pi        20   0  408508 141708  91368 S  21.7  14.9   0:41.16
chromium-browse
 1653 pi        20   0  397368 128960  91432 R  33.4  13.6   0:42.17
chromium-browse
 1653 pi        20   0  412652 141388  91560 S  32.5  14.9   0:43.15
chromium-browse
 1653 pi        20   0  562496 290220 138076 R  41.3  30.6   0:44.63
chromium-browse
 1653 pi        20   0  581256 310012 156836 S  36.0  32.7   0:46.82
chromium-browse
 1653 pi        20   0  578468 307180 156836 S  28.2  32.4   0:47.68
chromium-browse
 1653 pi        20   0  582564 311084 160492 S  34.2  32.8   0:48.72
chromium-browse
 1653 pi        20   0  535224 262184 156396 S  41.9  27.6   0:49.99
chromium-browse
 1653 pi        20   0  535224 262304 156396 S  40.4  27.7   0:51.21
chromium-browse
 1653 pi        20   0  458032 186452 156460 S  47.4  19.7   0:52.64
chromium-browse
 1653 pi        20   0  491640 220372 156652 S   9.2  23.2   0:52.92
chromium-browse
 1653 pi        20   0  569596 297956 194316 S  47.4  31.4   0:54.35
chromium-browse
 1653 pi        20   0  569596 297880 194316 S  35.2  31.4   0:55.42
chromium-browse
 1653 pi        20   0  569596 298184 194316 S  30.8  31.4   0:56.35
chromium-browse
 1653 pi        20   0  569676 298380 194316 S  33.2  31.5   0:59.08
chromium-browse
 1653 pi        20   0  569676 298304 194316 S  27.0  31.5   0:59.90
chromium-browse
 1653 pi        20   0  572464 301068 194316 R  26.2  31.7   1:00.69
chromium-browse
pi@raspberrypi:~$

 It was using upwards of 50% of (a) CPU at times, and a third of the
memory. Remember, this is on a 3B+ 1.4GHz quad-core processor. Straight
Raspbian install (2019-07-10 as I recall -- aka: NOOBS_v3_2_0.zip). No
experimental graphics drivers.


--
 Wulfraed                 Dennis Lee Bieber         AF6VN
 wlfraed@ix.netcom.com    http://wlfraed.microdiversity.freeddns.org/

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