There is a nice improvement in Fedora 18 related to yum and PackageKit. It fixes a long-standing issue that while PackageKit is active (e.g. checking for system updates), any yum usage is blocked. You would see messages like this:
$ yum install foo ... Another app is currently holding the yum lock; waiting for it to exit... The other application is: PackageKit Memory : 41 M RSS (447 MB VSZ) Started: Fri Sep 7 09:27:08 2012 - 23:13 ago State : Sleeping, pid: 1315 Another app is currently holding the yum lock; waiting for it to exit... The other application is: PackageKit Memory : 46 M RSS (452 MB VSZ) Started: Fri Sep 7 09:27:08 2012 - 23:15 ago State : Running, pid: 1315 ...
It could last from seconds to dozens of minutes. Killing PackageKit was often the only choice. For me, as a yum-only user, this was really painful and annoying.
But it is no longer the case! As you can see in Bug 812938, Elad Alfassa implemented a patch to PackageKit-yum-plugin and Richard Hughes incorporated it upstream. If you run yum in Fedora 18 now, it will send a signal to PackageKit to cancel any background operations, run your yum command almost immediately and then resume PackageKit operation. The fix turned out to be quite simple, which is ironic, because this issue caused a lot of grievance among our users.
Elad, Richard, thanks a lot!
And the lessons learned for the rest of us is that if you have at least decent technical knowledge and something troubles you, it’s worth to have a look at it. The solution might turn out quite simple. (Personally, I really miss some team in Fedora that would focus on these small issues that cause a lot of discomfort).
Thanks again, guys.