On Wednesday 29 November 2006 22:17, "Vladimir G. Ivanovic" <[EMAIL PROTECTED]> wrote about 'Re: [gentoo-user] [OT] HDD I/O and UI responsiveness': > Boyd Stephen Smith Jr. wrote: > > On Tuesday 28 November 2006 17:45, Dale <[EMAIL PROTECTED]> wrote > > about 'Re: [gentoo-user] [OT] HDD I/O and UI responsiveness': > >> I read somewhere that they are trying to 'nice' the drive usage like > >> they do the CPU. That may help if you can find it and enable it. I > >> think it is in some of the very new kernels if I read it correctly. > >> Sorry, I didn't bookmark it. < slaps hand > > > > > There's the ionice utility provided by... > > <Running equery> > > ...sys-process/schedutils. > > Isn't this just masking the problem?
Yes and no. > I don't see the CPU pegged, so why should other applications be > unresponsive? Because they aren't waiting to be scheduled on the CPU. They are waiting to be scheduled for I/O against a certain device. ionice will cause a process to be more likely to have interruptable I/O operations interrupted, allowing other non-ioniced processes to access the disk(s) with less latency. Dumping the contents of /dev/null to disk will slow other processes down even though your CPU will be used very little, because all your I/O is consumed. It is "masking" the problem that you are running out of I/O bandwidth / "latency" / "cycles". Of course, that's not actually that rare; I have a 6 disk RAID-5 array, and I can still make playing video from disk stutter, by performing I/O intensive tasks. -- "If there's one thing we've established over the years, it's that the vast majority of our users don't have the slightest clue what's best for them in terms of package stability." -- Gentoo Developer Ciaran McCreesh
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