Date: Sun, 08 Nov 1998 09:42:56 +0100 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: Bruce Evans <bde@zeta.org.au> Cc: wpaul@skynet.ctr.columbia.edu, current@FreeBSD.ORG Subject: Re: Grrr... calcru: negative time blah blah blah Message-ID: <14429.910514576@critter.freebsd.dk> In-Reply-To: Your message of "Sun, 08 Nov 1998 19:16:28 %2B1100." <199811080816.TAA18086@godzilla.zeta.org.au>
next in thread | previous in thread | raw e-mail | index | archive | help
In message <199811080816.TAA18086@godzilla.zeta.org.au>, Bruce Evans writes:
>Timecounter strangeness seems to be only a symptom here. I've seen
>similar strangeness caused by ddb masking interrupts. However,
>{micro|nano}[run]time() only have obvious problems when tco_delta()
>overflows a u_int. Overflow occurs after only about 10 seconds for
>a 400MHz tsc timecounter, but not for one hour for an i8254 timecounter.
Uhm, it happens earlier for a i8254, in fact it happens whenever more
than one interrupt is lost. The majority of the bits are software
bits.
>>Running sysctl debug _BEFORE_ triggering the problem by running the
>>X server shows this:
>>...
>>debug.tc_diag_maxforward: -692379806
>
>This apparently gets set to a bad value during initialization. There
>must be some sign extension bugs for a negative value to be the maximum.
sysctl doesnt know about unsigned ints.
--
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-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?14429.910514576>