[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: what is the sticky bit?

jim writes:
> Way back when (in the olden days), unix would exec a program by copying
> it into swap and then allowing the page mechanism to page it into memory
> for execution.

Way, way back in the *really* olden days (that is, five years ago when I
was still running System III on my Onyx) there was no paging.  "Swapping"
meant copying the entire process to the swap device.  There was shared
text, though.  This saved memory, and also time for programs like sh which
are always in use.  But what about vi or ls?  Silly to overwrite it when
somebody is going start it up sgain any minute now.  Thus the "save swapped
text" bit, also known as the "sticky bit": swap the instruction segment out
once only, and leave it on the swap device (or in memory, if it didn't get
swapped) even after the process terminates.
John Hasler                This posting is in the public domain.
john@dhh.gt.org		   Do with it what you will.
Dancing Horse Hill         Make money from it if you can; I don't mind.
Elmwood, Wisconsin         Do not send email advertisements to this address.

TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word "unsubscribe" to
debian-user-request@lists.debian.org . 
Trouble?  e-mail to templin@bucknell.edu .

Reply to: