[gclist] Re: gclist-digest V3 #106

John R Levine johnl@iecc.com
Wed, 20 Sep 2000 15:16:36 -0400 (EDT)

> My suggestion simply amounts to this: We have /dev/zero, which is very
> useful to us but has a property (zero filling) which costs us
> something and which we do not need.  A device like /dev/zero but
> without this property would be even better.

It seems to me that since you'd have to recycle old pages to avoid 
security problems, it'd make more sense to use a discardcontents() call 
to advise the system about pages that it can mark as available so it can 
reuse the page frame for something else if it needs the space, reuse the 
same page if it's touched again soon, or zero-fill if it's discarded and 

My question is how often you have pages like that.  My impression is not very
often.  Also remember that on sensible systems where address zero traps,
zero-filled pages catch a lot of dangling pointer bugs. 

John Levine, johnl@iecc.com, Primary Perpetrator of "The Internet for Dummies",
Information Superhighwayman wanna-be, http://iecc.com/johnl, Sewer Commissioner
Finger for PGP key, f'print = 3A 5B D0 3F D9 A0 6A A4  2D AC 1E 9E A6 36 A3 47