@fabnavigator If I let one sit on system activity for 30-45s or so I see:
PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU COMMAND
11 root 199 ki31 0B 32K CPU0 0 39.0H 79.30% [idle{idle: cpu0}]
11 root 199 ki31 0B 32K RUN 1 38.6H 78.52% [idle{idle: cpu1}]
29905 root 59 0 154M 59M accept 1 0:40 6.25% php-fpm: pool nginx (php-fpm)
28542 root 11 0 124M 54M piperd 1 0:32 3.12% php-fpm: pool nginx (php-fpm)
1427 root 59 0 158M 61M accept 1 0:40 1.71% php-fpm: pool nginx (php-fpm){php-fpm}
12 root -55 - 0B 336K WAIT 1 58:09 1.46% [intr{gic0,s42: mvneta0}]
12 root -55 - 0B 336K WAIT 1 31:36 1.42% [intr{gic0,s45: mvneta1}]
12 root -54 - 0B 336K WAIT 1 39:56 0.63% [intr{swi1: netisr 1}]
672 root 59 0 158M 62M accept 0 0:45 0.59% php-fpm: pool nginx (php-fpm)
nginx is the web server. Yours seems busier for some reason.
Another where I run top -aSH at the command line doesn't have the web activity of course, as I'm not even logged in to the web GUI:
PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU COMMAND
11 root 199 ki31 0B 32K RUN 0 376.2H 96.44% [idle{idle: cpu0}]
11 root 199 ki31 0B 32K CPU1 1 381.1H 95.49% [idle{idle: cpu1}]
12 root -54 - 0B 336K WAIT 1 64:56 3.46% [intr{swi1: netisr 1}]
2 root -54 - 0B 32K WAIT 0 341:50 1.38% [clock{clock (0)}]
12 root -55 - 0B 336K WAIT 0 108:14 1.13% [intr{gic0,s42: mvneta0}]
19591 root 0 0 14M 4608K CPU0 0 0:00 0.46% top -aSH
12 root -54 - 0B 336K WAIT 0 44:45 0.39% [intr{swi1: netisr 0}]
7 root -15 - 0B 16K pftm 0 37:46 0.37% [pf purge]
12 root -55 - 0B 336K WAIT 1 49:24 0.27% [intr{gic0,s45: mvneta1}]
I pulled up a rule to save it on the latter...~10s to log in, 2-3s to open the LAN rules page, 3-4s or so to apply. Just via counting.
I missed that it was a max in the subject line, that should eliminate any eMMC storage speed issues.