Ubuntu 19.10 freezes and lags reguarly

This is a regression that happened from Kernel from Kernel 5.0 to 5.3. This may be a problem in the recent changes that the 5.3 kernel introduced with the deprecated deadline, cfq and noop, which according to the Ubuntu wiki "prior to Ubuntu 19.04 with Linux 5.0 or Ubuntu 18.04.3 with Linux 4.15, the multiqueue I/O scheduling was not enabled by default and just the deadline, cfq and noop I /O schedulers were available by default". It has also been reported that some bugs have been introduced for those who have an intel and use the i965 driver.

To get around the problem i changed the swappiness kernel parameter to 10, and use bfq for IOSchedulers, by default Ubuntu uses mq-deadline.

I had a similar issue. I get temporary relief from turning swap off with sudo swapoff -a. It may be related to the usage of swap in the new kernel.

It seems this is a confirmed bug and is being investigated here https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1833281

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I managed to significantly reduce this problem in Ubuntu 19.10 by upgrading my kernel to 5.5.9. What I did:

• I went to https://kernel.ubuntu.com/~kernel-ppa/mainline/ and found the latest release of 5.5 after sorting by Last Modified.

• Under Build for amd64 succeeded, I downloaded four files: linux-headers-...-all.deb, linux-headers-...generic, linux-image-...generic, and linux-modules-...generic.

• Then I put them in a directory, went to terminal, cd'd to that directory, and ran sudo dpkg -i *.deb

That's all it took. It automatically installed the latest 5.5 kernel and created a grub entry that became the default. After a restart, no more lags or freezing mouse, at least they became more rare. Swap works normally again.

After update to ubuntu 19.10 I also get lags and freeze. Not sure this helps you, but my problem was in graphics drivers. I update drivers from https://launchpad.net/~oibaf/+archive/ubuntu/graphics-drivers and it works again.

First time i also think this was ssd problem because lags frequently occur when start new application or switch firefox tab.