Date: Sun, 3 Jul 2005 00:30:36 GMT From: Jason Bacon <bacon@smithers.neuro.mcw.edu> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/78711: Parallel printer incredibly slow Message-ID: <200507030030.j630UaNl014492@freefall.freebsd.org>
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The following reply was made to PR kern/78711; it has been noted by GNATS. From: Jason Bacon <bacon@smithers.neuro.mcw.edu> To: Bruce Evans <bde@zeta.org.au> Cc: freebsd-bugs@freebsd.org Subject: Re: kern/78711: Parallel printer incredibly slow Date: Mon, 14 Mar 2005 17:55:19 -0600 (CST) Mark another one resolved... sysctl hw.intr_storm_threshold=2500 seems to have done the trick. I printed a high quality photo from my iBook, and the job ran just fine. Top showed the CPU usage split between system and interrupt, whereas it was all system in polling mode as one might expect. I went back and checked my /var/log/messages from before the change, and noticed: Interrupt storm detected on "irq7: lpt0"; throttling interrupt source stray irq7 I also repeated the experiment for confidence: sysctl hw.intr_storm_threshold=500 re-ran same print job and watched it stall sysctl hw.intr_storm_threshold=2500 re-ran same print job and watched it complete If you're interested in collecting some data on the topic, I can play with the threshold values and look for a working minimum for my needs. Let me know, Jason On Sat, 12 Mar 2005, Bruce Evans wrote: > On Fri, 11 Mar 2005, Suporte Matik wrote: > >> On Friday 11 March 2005 19:42, Jason Bacon wrote: >>>> Description: >>> >>> The parallel printer runs ridiculously slow. It prints normally >>> for about 30 seconds, then prints one line every 5 or 10 minutes. >>> ... >> >> any two lines text file needs 15 minutes to be printed >> >>>> Fix: >>> >>> lptcontrol -s resolves the problem. This looks to me much >>> ... >> >> does not fix, the problem is as well with lpr and cups local/remote >> >> the only way to get "some more speed" is using b/w and 150 dpi on a HPDJ, >> any >> gray or color mode is slow > > Try changing the interrupt storm threshold (hw.intr_storm_threshold) to > something larger than the printer can generate. FreeBSD-5.3 has interrupt > storm detection that misdetects the very high interrupt rates that can > be caused by printers (combined with low quality interrupt handling in > the lpt driver) as interrupt storms. > >> doesn't matter what you set in the BIOS or whatever, any gray or colormode >> on >> 5.3 is that inacceptable slow >> >> using the exactly same printer and port settings on 5.2.1 or 4.11 brings >> you >> back to the expected printing speed > > FreeBSD-5.2 and FreeBSD-current have different bugs in interrupt storm > detection and handling. In at least some versions, the bugs make printers > go even slower if an interrupt storm is misdetected for them, but > misdetection is apparently rarer. > > FreeBSD-4 doesn't have interrupt storm detection, so any problems with > printer speed are local to the driver. > > Bruce > _______________________________________________ freebsd-bugs@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-bugs To unsubscribe, send any mail to "freebsd-bugs-unsubscribe@freebsd.org"
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