🚀 go-pugleaf

In article <59591@mimsy.umd.edu> alex@cs.umd.edu (Alex Blakemore) writes:
>In article <1992Aug10.152435.10393@svcdudes.com> moose@svcdudes.com writes:
>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.

sticky(8) says:

     [...] Shareable text seg-
     ments are normally placed in a least-frequently-used cache
     after use, and thus the `sticky bit' has little effect on
     commonly-used text images. [...]

This is just what you see when starting up an application, quitting it
and starting it up again (done on a machine with enough RAM): It comes
up much faster the second time, because it doesn't have to read the
files from the disk.

Do a 'cat <bigfile>' (or similar) followed by a 'filemem <bigfile>'.
You can see what is still in memory and doesn't need to be reloaded
again.

>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.

From what I've heard, the speed difference between a RAM disk and a
hard disk when used for temporary files is that creat()ing a file
flushes the directory block to the disk before returning.

-Marcel