Date: Sun, 29 Nov 1998 21:42:38 +0100 From: Poul-Henning Kamp <phk@FreeBSD.ORG> To: faq@FreeBSD.ORG Subject: entry on "calcru: negative time" Message-ID: <9419.912372158@critter.freebsd.dk>
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Q: My machine prints "calcru: negative time..." Q: My machine shoots processes down with "SIGXCPU exceeded cpu time limit" A: (FreeBSD-3 from 1998/11/29 forward): This can be caused by various hardware and/or software ailments relating to interrupts. It may be due to bugs but can also happen by nature of certain devices. Running TCP/IP over the parallel port using a large MTU is one good way to provoke this problem. Graphics accellerators can also get you here, in which case you should check the interrupt setting of the card first. If the problem cannot be fixed otherwise the solution is to set this sysctl variable: sysctl -w kern.timecounter.method=1 This means a performance impact, but considering the cause of this problem, you probably will not notice. If the problem persists, keep the sysctl set to one and set the "NTIMECOUNTER" option in your kernel to increasingly larger values. If by the time you have reached "NTIMECOUNTER=20" the problem isn't solved, interrupts are too hosed on your machine for reliable timekeeping. -- Poul-Henning Kamp FreeBSD coreteam member phk@FreeBSD.ORG "Real hackers run -current on their laptop." "ttyv0" -- What UNIX calls a $20K state-of-the-art, 3D, hi-res color terminal To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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