Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!pasteur!ames!purdue!haven!decuac!shlump.dec.com!michaud From: michaud@decvax.dec.com (Jeff Michaud) Newsgroups: comp.unix.ultrix Subject: Re: unaligned data access - Ultrix 3.0 (RISC) Keywords: DS3100 Ultrix 3.0 RISC Errors Message-ID: <3673@shlump.dec.com> Date: 21 Jul 89 21:44:00 GMT References: <18664@mimsy.UUCP> <861@hadron.UUCP> <2678@decuac.DEC.COM> Sender: news@shlump.dec.com Lines: 20 In article <18664@mimsy.UUCP>, steve@vorga.umiacs.umd.edu (Steve D. Miller) writes: > Does turning off the messages also turn off the fixups? Is there any way > to turn off the fixups, either on a per-process or systemwide basis? Turning off the messages only turns off the message going to the users terminal (ie. the uprintf's). They still go to the error logger (which can be looked at using uerf) so its a double performance killer, once for the fixup, and again because it has to log it through the error logging daemon. uac(1) can turn off the message on a per-process or systemwide basis. Turning it off for a process also turns it off for children of the process. Unaligned accesses are really bugs in the application. It is just that so maney of us have been spoiled by the VAX in being able to cast pointers to pointers to anything we like :-). Kernel hackers note that unaligned accesses in the kernel result in a panic (ie. no fixups in kernel mode). -- /--------------------------------------------------------------\ |Jeff Michaud michaud@decwrl.dec.com michaud@decvax.dec.com| |DECnet-ULTRIX #include | \--------------------------------------------------------------/