Date: Thu, 03 Oct 1996 15:14:31 +0200 From: Tor Egge <Tor.Egge@idt.ntnu.no> To: bde@zeta.org.au Cc: freebsd-hackers@freebsd.org Subject: Re: Interrupt lossage in FreeBSD-current. Message-ID: <199610031314.PAA15348@pat.idt.unit.no> In-Reply-To: Your message of "Thu, 3 Oct 1996 14:37:08 %2B1000" References: <199610030437.OAA32243@godzilla.zeta.org.au>
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> >But something was causing an RTC interrupt to be lost. I've only > >experienced it while profiling a program (while the RTC interrupt rate > >is 1024 Hz), thus I can only assume that the RTC does not like a > >latency longer than the interval between two RTC interrupts. > > Please check this. Disable interrupts for a second or two and see if > the RTC stops. Inserting an INTRDIS(IRQ8) in the load part of an lkm, and an INTREN(IRQ8) in the unload part showed that RTC interrupts stopped while the device was loaded, but resumed as soon as the device was unloaded. Inserting a loop taking 4 seconds while interrupts were disabled in the load part of the lkm just froze the system for 4 seconds, but RTC interrupts resumed afterwards. I no longer see this as a latency issue with regard to the RTC. Something else was causing one RTC interrupt to be lost. - Tor Egge
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