Autzoo.671 NET.v7bugs utzoo!henry Thu May 28 19:09:51 1981 disksort read/write order In /usr/sys/dev/dsort.c, the general seek-sort routine used by hp.c et al, the code as distributed queues reads before writes. This is WRONG, the intent was to put writes before reads (I asked Dennis Ritchie at the San Francisco Usenix meeting). The result is that on a very busy system, it can take a looooong time for data to get out to disk, which is risky and can hurt performance. The fix is simple; in the two if's that check B_READ flags, "ap" should be changed to "bp" and vice-versa. This bug has been known for some time, but hasn't been seen on the net yet. It was discovered by Peter Hardie at University of Saskatchewan. ----------------------------------------------------------------- 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.