Scheduling multi-core systems Swifty <Steve.J.Swift[ at ]gmail.com> 12/22/2008 5:19:27 AM In the good old days, when systems had just one processor, it was easy to stop a background task from hogging your system; you set it to idle priority. This no longer works, and the more processors you have, the worse the problem is. My system just started its daily backup, and that is so I/O bound that it seriously affects any other process doing disc I/O. Setting it to idle priority has almost no effect, as my system has enough CPU to keep up with everything that I'm doing, with plenty left over for the backup. Is there any simple mechanism to restrict a tasks I/O rate? I have one workaround - set it to idle priority, then start idle-priority program(s) that simply consume CPU in order to keep the backup at bay. This works, but it really shouldn't be necessary. And if you say that the backup should have its own I/O rate controls, then could you mention that to the Synctoy developers, please? :-) -- Steve Swift http://www.swiftys.org.uk/swifty.html http://www.ringers.org.uk

Re: Scheduling multi-core systems Leonard Grey <l.grey[ at ]invalid.invalid> 12/22/2008 1:45:42 PM Buy backup software that offers throttling as a feature. --- Leonard Grey Errare humanum est Swifty wrote: [Quoted Text] > In the good old days, when systems had just one processor, it was easy > to stop a background task from hogging your system; you set it to idle > priority. > > This no longer works, and the more processors you have, the worse the > problem is. > > My system just started its daily backup, and that is so I/O bound that > it seriously affects any other process doing disc I/O. > > Setting it to idle priority has almost no effect, as my system has > enough CPU to keep up with everything that I'm doing, with plenty left > over for the backup. > > Is there any simple mechanism to restrict a tasks I/O rate? > > I have one workaround - set it to idle priority, then start > idle-priority program(s) that simply consume CPU in order to keep the > backup at bay. This works, but it really shouldn't be necessary. > > And if you say that the backup should have its own I/O rate controls, > then could you mention that to the Synctoy developers, please? :-) >

Re: Scheduling multi-core systems Swifty <Steve.J.Swift[ at ]gmail.com> 12/22/2008 9:42:01 PM Leonard Grey wrote: [Quoted Text] > Buy backup software that offers throttling as a feature. Curiously, the backup software that I did purchase does support throttling, but even that has its problems. It is happy to throttle its I/O throughput, but only as long as it detects human activity (presumably it is watching keystrokes/mouse movements). This is fine, as far as I'm concerned, but when I stop using my PC, the backup runs full tilt, and really annoys my wife, who is trying to view webpages through our (now overloaded) router. I'll either start Synctoy earlier in the morning, or get up later in future. -- Steve Swift http://www.swiftys.org.uk/swifty.html http://www.ringers.org.uk