Messages in this thread |  | | Date | Mon, 6 Nov 2000 08:14:26 +0000 | From | Sean Hunter <> | Subject | Re: Loadavg calculation |
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Sorry, I know this is a little left-field, but how about redesigning your process so that instead of using a load_avg, you start all your calculations from a single server on each node? It could queue up incoming calculations, and fork a child to do each one.
Of course, it would catch a signal when the child died, so you'd immediately know when to start up another calculation. If you liked, it could check the one-minute load avg from time to time to see what would be a friendly level of calculations overall, adjust the overall level of concurrent child processes accordingly.
The timing, however, would still come from a signal, and would thus be instantaneous.
Or am I being totally dumb?
Sean
On Sun, Nov 05, 2000 at 07:55:40AM -0500, bobyetman@att.net wrote: > > I'm working a project a work that is using Linux to run some very > math-intensive calculations. One of the things we do is use the 1-minute > loadavg to determine how busy the machine is and can we fire off another > program to do more calculations. However, there's a problem with that. > > Because it's a 1 minute load average, there's quite a bit of lag time from > when 1 program finishes until the loadavg goes down below a threshold for > our control mechanism to fire off another program. > > Let me give an example (all on a 1-cpu PC) > > HH:MM:SS > 00:00:00 fire off 4 programs > 00:01:00 loadavg goes up to 4 > 00:01:30 3 of the 4 programs finish loadavg still at 4 > 00:02:20 load avg goes down to 1, below our threshold > 00:02:21 we fire off 3 more programs. > > We'd like to reduce that almost 50 second lag time. Is it possible, in > user-space, to duplicate the loadavg calculation period, say to a 15 > second load average, using the information in /proc? > > The other option we looked at, besides using loadavg, was using idle pct%, > but if I read the source for top right, involves reading the entire > process table to calculate clock ticks used and then figuring out how many > weren't used. > > Ideas, opinions welcome. Yes, I read the list, so either respond direct > to me, or to the list. > > bobyetman@att.net (Robert A. Yetman) > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > Please read the FAQ at http://www.tux.org/lkml/ > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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