Performance degradation on VGX

Henrik Klagges uh311ae at sun7.lrz-muenchen.de
Fri Nov 2 19:59:25 AEST 1990



Hello,                                                                    
                                                                              
in his posting elvis at 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=<number>" into the start of the GCOS field in /etc/passwd. This
  looks like this (cpcahil at 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 at sun7.lrz-muenchen.de OR @DM0LRZ01.BITNET


                                   
                         



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