Date: Tue, 2 May 2000 20:13:54 -0400 From: Garance A Drosihn <drosih@rpi.edu> To: Warner Losh <imp@village.org>, "Lorenzo Iania" <l.iania@sintesi.net> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: lpr: order of print requests Message-ID: <v04210101b5351bfcfef6@[128.113.24.47]> In-Reply-To: <200005012009.OAA18596@harmony.village.org> References: <017c01bfb11f$ab144c80$0500000a@sintesi.net> <200005012009.OAA18596@harmony.village.org>
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At 2:09 PM -0600 5/1/00, Warner Losh wrote: >LPR queues up the reuqests and prints them in order smallest to >largest to reduce the average wait time for a job at the expense of >having a larger standard deviation in the wait times for jobs. Maybe >this is what you are running into. I don't know if there's a way to >disable this behavior or not. At least that's what I recall lpd doing >years ago when I ran a unix lab in school. I didn't go check the code >to see if it still did that or not. FreeBSD's lpr, as it ships, does not do queue reordering based on size. It is probably best that it remain this way. In the case of postscript jobs, for instance, reordering a queue based on the byte-size of the postscript job is pretty pointless. You can have a short job which takes a long time to print, or a long job which pretty much flies right through the queue. The byte-size of the postscript job does not accurately indicate how long it will take to plot. Postscript is a language. Saying which job will print faster is like claiming you can tell which C-program will execute in less time based on the byte-size of the C source files. I am sure that many sites would change lpr's behavior to implement some kind of prioritization based on file size or file type, but lpr as exists in freebsd source is FIFO (assuming no one does an 'lpc topq' to explicitly change that order...). Looking at the source code (the getq() and compar() routines in lpr/common_source/common.c), it is clear that it only checks the last-modification time of the cf files for each job. 'lpc topq' works by altering those last-modification timestamps. --- Garance Alistair Drosehn = gad@eclipse.acs.rpi.edu Senior Systems Programmer or drosih@rpi.edu Rensselaer Polytechnic Institute To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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