Ubuntu 20.04 slows down after usage

I have a DELL laptop with Ubuntu 20.04. It's been a while that after some usage (e.g. firefox, some video-calls, etc.) it becomes slow. There are some processes which start to take higher percentage of cpu (even if they do not take the whole cpu). In this image there's the output of htop.

I don't understand why those processes keep my cpu usage high.

Any help is appreciated.

EDIT: As you can see in the image, I have 32 GB of Ram. The computer slows down depending on what I do. Also youtube videos slow down my laptop. At the beginning (one month ago) it was much faster. I also tried to re-install Ubuntu but it didn't get better.

EDIT2: Some more command outputs from the command lineand

EDIT3:

francesco@dell-latitude-inria:~/Desktop$ sudo lshw -C video *-display description: VGA compatible controller product: UHD Graphics 620 (Whiskey Lake) vendor: Intel Corporation physical id: 2 bus info: pci@0000:00:02.0 version: 02 width: 64 bits clock: 33MHz capabilities: pciexpress msi pm vga_controller bus_master cap_list rom configuration: driver=i915 latency=0 resources: irq:165 memory:cb000000-cbffffff memory:80000000-8fffffff ioport:3000(size=64) memory:c0000-dffff

then

francesco@dell-latitude-inria:~/Desktop$ sudo lshw -C memory *-firmware description: BIOS vendor: Dell Inc. physical id: 0 version: 1.12.0 date: 02/24/2021 size: 64KiB capacity: 32MiB capabilities: pci pnp upgrade shadowing cdboot bootselect edd int13floppynec int13floppy1200 int13floppy720 int13floppy2880 int5printscreen int9keyboard int14serial int17printer acpi usb smartbattery biosbootspecification netboot uefi *-memory description: System Memory physical id: 20 slot: System board or motherboard size: 32GiB *-bank:0 description: SODIMM DDR4 Synchronous 2667 MHz (0,4 ns) product: HMA82GS6JJR8N-VK vendor: Hynix Semiconductor (Hyundai Electronics) physical id: 0 serial: 2FA26C44 slot: DIMM A size: 16GiB width: 64 bits clock: 2667MHz (0.4ns) *-bank:1 description: SODIMM DDR4 Synchronous 2667 MHz (0,4 ns) product: HMA82GS6JJR8N-VK vendor: Hynix Semiconductor (Hyundai Electronics) physical id: 1 serial: 2FA26909 slot: DIMM B size: 16GiB width: 64 bits clock: 2667MHz (0.4ns) *-cache:0 description: L1 cache physical id: 29 slot: L1 Cache size: 256KiB capacity: 256KiB capabilities: synchronous internal write-back unified configuration: level=1 *-cache:1 description: L2 cache physical id: 2a slot: L2 Cache size: 1MiB capacity: 1MiB capabilities: synchronous internal write-back unified configuration: level=2 *-cache:2 description: L3 cache physical id: 2b slot: L3 Cache size: 8MiB capacity: 8MiB capabilities: synchronous internal write-back unified configuration: level=3 *-memory UNCLAIMED description: RAM memory product: Cannon Point-LP Shared SRAM vendor: Intel Corporation physical id: 14.2 bus info: pci@0000:00:14.2 version: 30 width: 64 bits clock: 33MHz (30.3ns) capabilities: pm cap_list configuration: latency=0 resources: memory:cc320000-cc321fff memory:cc32b000-cc32bfff

then

francesco@dell-latitude-inria:~/Desktop$ ls -al ~/.local/share/gnome-shell/extensions
total 12
drwxrwxr-x 3 francesco francesco 4096 mai 19 11:47 .
drwx------ 3 francesco francesco 4096 mai 28 13:39 ..
drwxrwxr-x 4 francesco francesco 4096 mai 19 11:47 

then

francesco@dell-latitude-inria:~/Desktop$ ls -al /usr/share/gnome-shell/extensions
total 20
drwxr-xr-x 5 root root 4096 avril 23 2020 .
drwxr-xr-x 7 root root 4096 mai 19 09:16 ..
drwxr-xr-x 2 root root 4096 mai 19 09:17 desktop-icons@csoriano
drwxr-xr-x 3 root root 4096 mai 19 09:17
drwxr-xr-x 3 root root 4096 mai 19 09:17 

then

francesco@dell-latitude-inria:~/Desktop$ snap list
Name Version Rev Tracking Publisher Notes
canonical-livepatch 9.6.2 99 latest/stable canonical✓ -
core 16-2.50 11081 latest/stable canonical✓ core
core18 20210507 2066 latest/stable canonical✓ base
core20 20210429 1026 latest/stable canonical✓ base
gimp 2.10.24 372 latest/stable snapcrafters -
gnome-3-28-1804 3.28.0-19-g98f9e67.98f9e67 145 latest/stable canonical✓ -
gnome-3-34-1804 0+git.3556cb3 66 latest/stable/… canonical✓ -
gtk-common-themes 0.1-52-gb92ac40 1515 latest/stable/… canonical✓ -
snap-store 3.38.0-59-g494f078 518 latest/stable/… canonical✓ -
snapd 2.50 11841 latest/stable canonical✓ snapd
telegram-desktop 2.7.4 2637 latest/stable telegram.desktop -

EDIT 4:

When trying to open an application (firefox, or visual studio code) what happens is that they take a LOT of CPU at the beginning and then not anymore, but still the system is slow

top - 17:30:58 up 27 min, 1 user, load average: 1,82, 3,20, 3,41
Tasks: 296 total, 6 running, 290 sleeping, 0 stopped, 0 zombie
%Cpu(s): 54,5 us, 8,0 sy, 0,0 ni, 37,3 id, 0,2 wa, 0,0 hi, 0,1 si, 0,0 st
MiB Mem : 31930,6 total, 26496,8 free, 2301,1 used, 3132,8 buff/cache
MiB Swap: 2048,0 total, 2048,0 free, 0,0 used. 28361,5 avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 10409 frances+ 20 0 4475420 120928 61060 R 167,8 0,4 0:09.46 code 10341 frances+ 20 0 50,5g 255440 111076 R 159,3 0,8 0:15.14 code 10382 frances+ 20 0 4508992 139532 66160 R 57,0 0,4 0:03.10 code 10394 frances+ 20 0 36,4g 169484 93784 S 30,3 0,5 0:07.08 code 1842 frances+ 20 0 5270364 291192 105076 S 16,9 0,9 4:10.51 gnome-shell 10309 frances+ 20 0 543340 125196 89264 R 14,3 0,4 0:01.81 code 10279 frances+ 20 0 4775044 144700 106712 S 14,0 0,4 0:01.71 code 1683 frances+ 20 0 869272 78712 43672 R 10,7 0,2 2:25.79 Xorg 9860 frances+ 20 0 968660 54596 41608 S 5,9 0,2 0:02.94 gnome-terminal- 10450 frances+ 20 0 10896 5096 3460 S 5,9 0,0 0:00.18 bash 10430 frances+ 20 0 4475432 76348 60928 S 4,6 0,2 0:00.83 code 768 root 20 0 273900 9404 8544 S 3,3 0,0 0:38.77 thermald 10328 frances+ 20 0 256532 77572 68320 S 3,3 0,2 0:00.16 code 9300 frances+ 20 0 3994300 430172 221396 S 1,6 1,3 2:10.01 firefox 9877 frances+ 20 0 12132 4200 3260 R 1,6 0,0 0:01.59 top 9192 root 20 0 0 0 0 I 1,3 0,0 0:01.29 kworker/5:3-events 9598 frances+ 20 0 2882896 254248 156000 S 1,3 0,8 1:19.61 Web Content 9510 frances+ 20 0 2496384 140660 96472 S 0,7 0,4 0:13.56 WebExtensions 

1 Answer

partial answer...

In reviewing /var/log/syslog around the suspected time of slowdown, I come away with these processes that need investigation...

• remarkable - lots of network errors
• livepatch - performing updates
• telegram - real time priority
• gnome-shell - window manager errors (do you have any themes installed?)

Update #1:

Reviewed 2nd syslog...

• lots of wireless disconnects/reconnects
• gnome-shell crash

Update #2:

• the code application is using a lot of CPU%