On Friday 12 October 2007 11:10:02 Gordon Henderson wrote: > On Fri, 12 Oct 2007, Tilghman Lesher wrote: > > On Friday 12 October 2007 10:29:24 Philipp Kempgen wrote: > >> Atis Lezdins wrote: > >>> I have 8-core system that has web interface + sql + java + some other > >>> stuff running, and at 30 simultenous calls i get loadavg maximum of 3. > >> > >> I wouldn't be too happy about a system with a > >> loadavg of 3. > > > > I dunno, 3 wouldn't be terrible on a 4 processor or 8 processor system, > > which isn't getting to be nearly as rare as it once was. > > Don't get too hung-up on load average under Linux. It's not always > indicative of the real "load" on the machine, it merely indicates the > number of processes running, or avalable to run - so if a process is > waiting on IO, it's 'running' and will get counted. I've seen servers (non > asterisk) with huge load averages but ones which were still usable because > the processes were waiting on IO from a slow device, (eg. remote NFS > mounts) so there was plenty of CPU left for computational tasks, etc. > > So 3 threads reading or writing to/from a TDM card might well spend most > of their time waiting for the IO to complete (clock in/out the A/D, A/D > convertors for example), give a load avg. of 3, yet the CPU should be > avalable for other tasks like shoveling RTP data over Ethernet for > example...
Are you saying that Linux makes no differentiation between long and short wait states? That would be a fairly major abrogation of the spec. I do know of a legal way (under the definition) to drive a load average higher: simply release the processor resource prematurely with either a usleep(1) or a sched_yield(). The definition of load average depends implicitly upon a process using its entire timeslot on the processor; if a process does significantly less, the load average will rise without a corresponding increase in actual CPU work. -- Tilghman _______________________________________________ --Bandwidth and Colocation Provided by http://www.api-digital.com-- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users