Asri-unix.570 net.unix-wizards utcsrgv!utzoo!decvax!ucbvax!hpvax!sri-unix!mike@BRL Mon Jan 18 21:09:31 1982 Sticky Programs. /tmp in memory Mike - Our system has lots of stuff sticky, and it DOES make a big difference. Especially because swapping is on a separate controller from the D-space fetch. Being sticky saves CPU time (1 DMA -vs- many, no block copying) and I/O time (1 continuous operation -vs- many). They payoffs are less substantial, but still noticable, if you swap on the same controller as /usr is on. Putting /tmp out in memory is a win, but putting it out on the UNIBUS as a real controller has certain advantages. Most importantly, the xfer from the /tmp memory to the buffer cache is DMA for a real controller, but it is a software copy the other way. Of course, there is the interupt overhead to pay when emulating a real disk. Either way is a big win over doing nothing. Cheers, -Mike ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.