Date: Fri, 17 Dec 1999 01:31:53 +0800 From: Peter Wemm <peter@netplex.com.au> To: nate@mt.sri.com (Nate Williams) Cc: Poul-Henning Kamp <phk@critter.freebsd.dk>, Kevin Day <toasty@dragondata.com>, dillon@apollo.backplane.com (Matthew Dillon), gallatin@cs.duke.edu (Andrew Gallatin), freebsd-current@FreeBSD.ORG Subject: Re: Serious server-side NFS problem Message-ID: <19991216173153.C526E1CC6@overcee.netplex.com.au> In-Reply-To: Message from Nate Williams <nate@mt.sri.com> of "Thu, 16 Dec 1999 10:18:48 MST." <199912161718.KAA19547@mt.sri.com>
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Nate Williams wrote: > > In message <199912160758.BAA87332@celery.dragondata.com>, Kevin Day writes: > > > > >Ack, I was using this very same thing for several devices in an isolated > > >peer-to-peer network to decide who the 'master' was. (Whoever had been up > > >longest knew more about the state of the network) Having this change could > > >cause weirdness for me too... I assumed (without checking *thwap*) that > > >boottime was a constant. > > > > > >Perhaps a 'real_boottime' or 'unadjusted_boottime' that gets copied after > > >'boottime' gets initialized so that others can use it, not just NFS? :) > > > > no, I think that is a bad idea. In your case you want to use the > > "uptime" which *is* a measure of how long the system has been > > running. > > Uptime is also a constantly changing number. Forgive me for my > ignorance, but why does bootime constantly change? I would have thought > it would be a constant? I've got software that also uses this to > determine when a new copy of it exists (although I do keep a local cache > of the value in case my software crashes, since it can recover from a > crash, but not a reboot). > > I would think that boottime would be constant, since you didn't keep > booting at a different time... Uptime is a monotonically increasing time starting at zero. Whenever the time-of-day adjusts to add or remove time, rather than changing the "uptime", we change the "origin" of timeofday and boottime. This means that we don't have to walk the entire process list and intercept all the timers and adjust them for the changing number of ticks in uptime etc. Cheers, -Peter To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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