[comp.unix.microport] sticky bit

trevor@trevan.UUCP (trevor) (07/07/89)

	Please could anyone tell me if the sticky bit works in Microport
System V/AT 286. In otherwords does it support shared text segments and
if so does anything special have to be done to the executable file.
		thanks trevor

vandys@hpcupt1.HP.COM (Andrew Valencia(Seattle)) (07/11/89)

/ hpcupt1:comp.unix.microport / trevor@trevan.UUCP (trevor) /  4:23 am  Jul  7, 1989 /

>	Please could anyone tell me if the sticky bit works in Microport
>System V/AT 286. In otherwords does it support shared text segments and
>if so does anything special have to be done to the executable file.

	The sticky bit is NOT shared text.  The sticky bit indicates that
you wish the data structures associated with the text segment to not go
away when you exit your program.  Because of the way swap space is allocated
this means that the swap resources will also hang around.  All of this
intends to reduce the startup time for running oft-used executables.

	The only special consideration for sticky executables is that you
really, REALLY don't want to set this bit on code which is under development--
the old stuff will stick around on your system until you reboot, making it
tricky to try new versions of the code.

	In general, with demand-load executables, page caches, and fast
/bin and /usr/bin disks, the original sticky bit concept is meaning less
each year.  Because of this, some manufacturers have started ignoring
the sticky bit.  Others have instead used it as a simple performance
hint--for instance, age the pages of such executables less often.

					Andy Valencia
					...!hplabs!hpda!vandys