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Since upgrading to Ubuntu 19.10, my system seems to freeze every couple of minutes, each time for a couple of seconds at a time. Mouse, keyboard and screen are all unresponsive during this time. When using Wayland, any keys that were pressed are repeated as if it was held the entire time (with Xorg this doesn't happen, but still freezes).

The freeze only seems to happen when the system is busy (e.g. opening a Chrome tab), but I haven't been able to isolate this specifically to high memory, CPU or disk access.

System details:

  • Ubuntu 19.10, Gnome Shell (not Unity).
  • Dell XPS 13 9370
  • 16GB RAM
  • 512GB SSD. Encrypted with LUKS/cryptsetup, then partitioned with LVM. EXT4 main partition, as well as 16GB swap space (barely in use).
  • Intel Core i7-8550U CPU
  • Killer 1435 802.11ac Wi-Fi
  • 2x 4K screens

Is there any way to debug what is causing this? I've checked system logs (dmesg; journalctl -b0), but I couldn't see anything significant. Where should I go to file a bug? I have no idea if this is an issue with my laptop, Ubuntu, or specific software I've installed.

Ralf
  • 487

1 Answers1

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Because this is a complete freeze, that only started occurring after an Ubuntu upgrade, some interaction between the kernel and hardware is the most likely culprits.

A good resource is the archlinux wiki on the machine: https://wiki.archlinux.org/index.php/Dell_XPS_13_(9370)

Some things to try from there included:

  • Disable NQC for the drive: No visible effect on performance or the freeze).
  • Upgrade the firmware for the SSD: Doubled the write throughput (impressive), but no effect on the freeze.
  • Disable some sleep states of the SSD: no visible effect.

What did fix the freeze is downgrading the kernel from the default 5.3 to mainline 5.1, using the instructions from here: https://wiki.ubuntu.com/Kernel/MainlineBuilds

Unfortunately I still have no idea what in the kernels are different to cause the freeze.

Update: Appears to be the same issue as in Ubuntu 19.10 freezes and lags reguarly

Ralf
  • 487