Comment 417 for bug 131094

Thanks for driving this forward.

You argue from
> So let us make one thing clear, IMHO if something overloads your machine with disk I/O it has to stall it.

This is a bit tricky, because overload means that the machine will be able not complete all task in the time given, i.e. tasks will accumulate until the resources are exhausted. Though, we usually do not have this situation on desktop machines. There we have tasks to do and want them to complete as fast as possible, thought some tasks may take longer than others. For example, copying a 5 GB DVD disk will take some minutes or so, but refreshing the browser window or switching windows should never. Overlay here would mean the user will turn of the machine and by a windows licence.

So this bug is mostly about having too big delays in applications using only a small bit of the available resources (like when switching back to a libreoffice window) when some other applications (like background file indexing) are asking for the remaining disk io resource capacities.

> Code improves to mitigate effects but can never be perfect for *ALL* users at once (especially in the default config)

I do not agree. Desktop responsiveness was achieved with older ubuntu versions on the given hw and is achieved with other operating systems (windows) on a broad range of hardware. I believe desktop responsiveness is something sufficiently specific a cpu and io scheduler can be tuned to. Using cgroups and alike might help, but should be configured by Ubuntu by default if necessary.