andrew@frip.gwd.tek.com (Andrew Klossner) (12/12/87)
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"As you know, UNIX does writes when it feels like it, and uses
any available in core blocks to read from. So if a program
started and finished between /etc/update's sync's, the only
disk overhead would be that of creating and deleting a
directory entry which is done synchronously."
On my system, the major use of /tmp files is for one phase of a
compiler to pass information to the next. The close in the first
(writing) phase seems to force the blocks to disk. Or does it?
"If you declare /tmp as a disk, you will be keeping two copies
of the most recently used blocks in core."
You'll only have two copies (one in the virtual /tmp) if you would
otherwise have written a copy to disk (to the real /tmp). Sounds like
a win to me.
-=- Andrew Klossner (decvax!tektronix!tekecs!andrew) [UUCP]
(andrew%tekecs.tek.com@relay.cs.net) [ARPA]levy@ttrdc.UUCP (Daniel R. Levy) (12/13/87)
In article <9513@tekecs.TEK.COM>, andrew@frip.gwd.tek.com (Andrew Klossner) writes: >On my system, the major use of /tmp files is for one phase of a >compiler to pass information to the next. The close in the first >(writing) phase seems to force the blocks to disk. Or does it? No, the blocks haven't necessarily gone to disk yet even on close. The blocks will go to disk in a short time thereafter, though, the time depending on the system and how it was set up. Some systems depend upon an /etc/update (or similar) daemon, which invokes the sync() system call on a periodic basis to cause buffered blocks to be written to disk. Others (like System V) have this periodic update functionality built into the kernel. -- |------------Dan Levy------------| Path: ..!{akgua,homxb,ihnp4,ltuxa,mvuxa, | an Engihacker @ | <most AT&T machines>}!ttrdc!ttrda!levy | AT&T Computer Systems Division | Disclaimer? Huh? What disclaimer??? |--------Skokie, Illinois--------|