Re: Oscillations in disk write compaction, poor interactive performance

Pavel Machek
2001-04-16T21:17:39Z

Hi!

> It also seems that in the 2.4 kernels, we can get into a sort of
> oscillation mode, where we can have long periods of disk activity
> where nothing can get done - the low points, where only 2-3 writes
> per second can occur, so completely screw up the interactive
> performance that you simply have to take your hands off the
> keyboard and go get coffee until the disk writes complete. I know
> we get better performance overall this way, but it can be
> frustrating when this occurs in the middle of video capture.

I see oscilation even in 2.2.X case....

Can you try running while true; do sync; sleep 1; done? It should help.

If it helps, try playing with bdflush/kupdate or how is it called/ parameters.

--
Philips Velo 1: 1"x4"x8", 300gram, 60, 12MB, 40bogomips, linux, mutt,
details at http://atrey.karlin.mff.cuni.cz/~pavel/velo/index.html.