🚀 go-pugleaf

In article <1992Aug10.152435.10393@svcdudes.com> moose@svcdudes.com writes:
> How about if instead of calling it a Ramdisk we call it a memory lockin program.   
> That means that whatever you put on the Ramdisk won't swap out.  I would love  
> to put things like cc and ccp and compiled headers on a Ramdisk to speed up my compiles.

Does the sticky bit work on Mach executables?

On older Unices you could get an even faster load of executables by
  chmod -t cc
to keep the text segment in RAM between invocations.

With a RAM disk, the text segment will have to be copied to another RAM
location at each invocation - unless Mach copy on write optimizations
take place (which seems doubtful if going through an interface for device drivers)

Good Unix filesystems cache recently read blocks - so why fix 
certain files in RAM based on your perception of what files are 
accessed most frequently?  Especially when the OS does so automatically, 
is more sensitive to changing usage patterns and caches at a finer
granularity (blocks instead of files)

There may be some uses for a RAM disk, but I suspect most users would
be better off just letting Mach's excellent virtual memory do its job.
Perhaps tuning an OS parameter or setting the sticky bit on frequently
used executables might help some.  The NeXT is not an old PC on Mac
with no or weak VM where RAM disks help alot.
-- 
---------------------------------------------------
Alex Blakemore alex@cs.umd.edu   NeXT mail accepted