🚀 go-pugleaf

Alex Blakemore <alex@cs.umd.edu> writes (reformatted):
>In article [...] 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?

Checking the man pages (hey, *there's* a new idea ;-) reveals the
following, from sticky(8).

# STICKY TEXT EXECUTABLE FILES
#      While the `sticky bit' is set on a sharable executable file,
#      the text of that file will not be removed from the system
#      swap area.  Thus the file does not have to be fetched from
#      the file system upon each execution.  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.
# 
#      Sharable executable files are made by the -n and -z options
#      of ld(1).
# 
#      Only the super-user can set the sticky bit on a sharable
#      executable file.
....
# BUGS
#      Since the text areas of sticky text executables are stashed
#      in the swap area, abuse of the feature can cause a system to
#      run out of swap.

What this tells us is that the machine does a pretty good job without
people messing with sticky bits for executables. Anyone who has a decent
amount of memory and has started a big program (say Mathematica), quit,
and started it again ought to have noticed the lack of chirping sounds
from the hard drive and the increase in speed second time around.

> 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.

I'm in total agreement here.

Oh, I've worked out what the next cool use for a RAM disk is, use it
for the swapfile! 			( Yes, this is meant to be a JOKE )

Regards,

   Richard.

P.S.
If this patronizing or condescending, my appologies - it is kind of late
as I write this... No offence meant to any of the posters I am replying
to.
-- 
Composing a suitably apt and witty | richard@smaug.questor.wimsey.bc.ca
signature and disclaimer is left   | oneill@fornax.UUCP | NeXTmail OK, but
as an exercise for the reader.     | oneill@cs.sfu.ca   | not >100K OK!