Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!sol.ctr.columbia.edu!ira.uka.de!fauern!lan!sun7.lrz-muenchen.de From: uh311ae@sun7.lrz-muenchen.de (Henrik Klagges) Newsgroups: comp.sys.sgi Subject: Re: Performance degradation on VGX Keywords: Priorities, Sticky bit, undoc feature in passwd Message-ID: <5296@tuminfo1.lan.informatik.tu-muenchen.dbp.de> Date: 2 Nov 90 08:59:25 GMT Sender: news@lan.informatik.tu-muenchen.dbp.de Reply-To: uh311ae@sun7.lrz-muenchen.de() Organization: LRZ, & STM Group at LMU Munich Lines: 37 Hello, in his posting elvis@athena.ee.msstate.edu writes about the severe performance degradation that occurs when his system is fully loaded. This is no surprise, even on a multiple CPU engine 8). If you specifically want to decrease the console response times or speed up certain programs, however, there are some possibilities to do this. - Start the appropriate processes with the "nice" command. As superuser, you can run processes with higher priority - eg., your console csh. - Attach the "sticky bit" to important programs (HANDLE WITH CARE !). This keeps a programs image in core even if it is getting rescheduled. => no swapping, but you can lock up your core quickly. This is done with "chmod -1xxx. xfile." (xxx=755, or whatever you like). - There is an undocumented feature in the /etc/passwd file. It allows you to give any login a non-standard priority. So you could change ie. the priority of the NeWS-Server itself, maybe. This works as follows: Insert a "pri=" into the start of the GCOS field in /etc/passwd. This looks like this (cpcahil@virtech.UUCP): root:GSDXoZZuPItTc:0:3:pri=-20-Admin(0000):/:/bin/csh ^^^^^^^ This gives root the highest possible user priority: 20(standard) -20 = 0. Yours Henrik Klagges STM group at LMU Munich uh311ae@sun7.lrz-muenchen.de OR @DM0LRZ01.BITNET