GPWRDCS@gp.govt.nz (Don Stokes, GPO) (09/02/89)
In article <2389@auspex.auspex.com>, guy@auspex.auspex.com (Guy Harris) writes: >>I must be lucky then. VMS has had one since day one. Working set >>parameters can be set by either authorization information, as parameters >>to the $CREPRC system service (which creates a process) or explicitly >>during process execution (SET WORKING_SET command, or $ADJWSL system >>service). > > OK, so which of the OSes that support working set scheduling do so > without having to be told by some external agent what the working set of > a process at some given time is? (Do the VMS calls even tell the OS > that, or do they just tell it how big the working set is?) The parameters tell the OS what the *limits* are, not what the working set size actually is. The idea being that programmers et al have a much better idea of what a particular process is going to use than the OS ever will. You basically provide the general "shape" of what the process is going to want, and the OS fine-tunes it according to what is actually happening to the process, and what resources are available. Most of the time you just provide one set of parameters for all users, and the OS does the rest. Basically, the parameters allow the working set system to be tweaked according to the site's workload and processing requirements. > Jerry Leichter claimed that the VMS software people showed that a > reference bit is not necessary. [...] I think Jerry has explained that more than adequately, or at least much better than I could. Don Stokes, Systems Programmer / / Domain: don@gp.govt.nz Government Printing Office, /GP/ PSImail: PSI%0530147000028::DON Wellington, New Zealand / / Bang: ...!uunet!vuwcomp!windy!gpwd!don -------------------------------------------------------------------------------- He who laughs last probably made a backup.