While trying to sketch a simple line the kirta program simply stops responding for a duration of 5 - 10 seconds before resuming again. The pauses are sporadic and unpredictable, but are enough to make attempting any project an annoying chore.
I'm sorry, but we cannot do anything with this bug report. A bug is something in Krita's code that we can fix. This is something that is happening on your system, not something that everyone experiences. In order to start guessing what might be up, we'd need to at least know the version of Krita you're using, what hardware you're using, what else is running on your system, what size and channel depth your images are working with and possibly other things as well. Here are some hints you could start with: https://docs.krita.org/en/KritaFAQ.html#krita-is-slow