RDSL and ignoring feedback
Posted Aug 2, 2007 8:00 UTC (Thu) by renox
In reply to: RDSL and ignoring feedback
Parent article: Still waiting for swap prefetch
The thing that this complaint show is that a 'fair scheduler' in itself is not good enough for enduser desktop..
If you have an application APP that is important to you, you renice it so it has lots of CPU, fine, but then say that this application sends a lot of work to do for the X server (could be any server really), then there is a kind of 'priority inversion' which happens where APP is slowed down because the X server doesn't have a big enough CPU share..
It's quite difficult to solve.. The only way would be to have some way to transfer the 'CPU token' that APP have to the server it's asking to do some work on its behalf, if it is a multi-threaded server which use a different thread for each client, then maybe the kernel could understand what's happening and boost the corresponding server's thread priority accordingly, but in a non-threaded server, I don't see how it could be solved even if the APP says gives my 'CPU token' to server X, how could the server X would be able to report/understand that currently he is supposed to be working for client APP and not for another client?
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