coreos-installer: downloads/installs slowly

In kola testiso we spawn a local webserver and point qemu at it. The legacy installer downloads and writes to disk in about one second. This new one takes…about 4 minutes. Something must be going terribly wrong 😄

I didn’t bother to try to debug this much yet, but it seems like the host webserver is spending a lot of time idle.

About this issue

Original URL
State: open
Created 4 years ago
Comments: 17 (17 by maintainers)

Commits related to this issue

WIP: run decompression/progress in separate thread from writes Attempt at fixing https://github.com/coreos/coreos-installer/issues/184 but doesn't seem to help. — committed to cgwalters/coreos-installer by cgwalters 4 years ago

Most upvoted comments

#290 switched to a copy() implementation with a larger buffer.

bgilbert on Jul 7, 2020

BTW I learned about the cool profiler GUI above from this: https://www.reddit.com/r/rust/comments/g0wkp0/til_firefox_profiler_makes_an_awesome_gui_for_perf/

cgwalters on Apr 24, 2020

Here’s a profile from current git master:

https://perfht.ml/2xLdVoJ

Basically I think what this is saying is that we are losing out by doing decompression and I/O on the same core - this type of thing is where classical Unix pipelines like curl | gunzip > /dev/disk win.

cgwalters on Apr 24, 2020