The suggestion is: if the non-BOINC CPU load on a 4-CPU system is 25%, BOINC should use only 3 CPUs. Seems reasonable to me. Comments? -- David
-------- Original Message -------- Subject: RE: Enhancement suggestion: CPU Usage exceeds parameter Date: Tue, 3 Aug 2010 20:57:43 -0400 From: Sean White <[email protected]> To: 'David Anderson' <[email protected]> I though NCPU's was not the % of CPU's, but the number BIONC was allowed to use? In the parameters panel - this is listed as % of processors - so if this is the units, then your expression makes sense. How would you mange the current 'over allocation' allowed which allows you to fully task the CPU's as well as GPU's? Or -- if the over allocation is A, then BIONC would allow for peak processor usage to spike to NCPU's-X+A, and continue to push? The reason for a more involved process would be to attempt to detect when the user or another pre-scheduled task is actually using the computer (i.e. gaming, watching a video, video recording etc) where the user experience or task is often time sensitive and may peak to higher usage levels. The more complicated approach assumes that the only tasks running on the computer that would consume any significant fraction of a single CPU's time are 'critical' or 'important' tasks. Assuming that there is some element of time-criticality to any of these means that BIONC would need to back off further than just "x" to give sufficent room as to minimize the time critical impact. I suppose that this could be done by monitoring both the average non-BIONC CPU usage over a period as well as the Standard deviation of the CPU usage. If the average is over a threshold (configurable?) then BIONC scales back by X + 2 Standard Deviations to ensure that overhead is available proportional to the peak processor usage over a period. If the average usage is below the threshold, the 'noise' is ignored. -Sean. -----Original Message----- From: David Anderson [mailto:[email protected]] Sent: Monday, August 02, 2010 7:09 PM To: Sean White Cc: BOINC Developers Mailing List Subject: Re: Enhancement suggestion: CPU Usage exceeds parameter That's a good idea. I'd been thinking about something similar. What I was thinking was to eliminate the preference, and just change things so that if non-BOINC CPU usage is X, BOINC will use at most NCPUs - X. -- David On 26-Jul-2010 2:37 PM, Sean White wrote: > David, > > > I've been a longtime BIONC fan, and had an 'enhancement' suggestion with > respect to the 'cpu usuage' exceeds 'parameter' feature. Instead of > shutting down the entire set of processess when the cpu usage exceeds a > threshold, it would make more sense to roll back usage 1 CPU at a time. > > If a computer has Y CPU's available for use, and the 'other process > usage' parameter is set to value X, then when Non-BIONC Usage /Y > X for > a minimum time interval 'T', then we freeze one BIONC process, freeing 1 > CPU to manage the non-BIONC tasks. The next trip occurs when Non-BIONC > usage / Y > (1/Y+X). (I.e. when the non-BIONC tasks load up the 1 CPU > and start impinging on the 2^nd CPU, we drop the second CPU out). I > would suggest that a reasonable 'drop out time' is 1s or so? (whatever > is currently used). > > This approach would eliminate the annoying 'entire BIONC all tasks > offline' event which I encounter when multiple tasks happen to end at > the same time, or when you open another application that happens to need > all of 1 CPU briefly to get going. > > Cheers, > > > Sean W. > _______________________________________________ boinc_dev mailing list [email protected] http://lists.ssl.berkeley.edu/mailman/listinfo/boinc_dev To unsubscribe, visit the above URL and (near bottom of page) enter your email address.
