This looks like a very hard bug to reproduce. I'm reluctantly going to recommend "Ignore for now".
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Lars Ellenberg Sent: Thursday, July 02, 2009 8:17 AM To: [email protected] Subject: Re: [Linux-HA] [patch] clock_t wrapped aroundcausingfalse resourcestart failure On Thu, Jul 02, 2009 at 11:00:08AM +0200, Dejan Muhamedagic wrote: > > if (cmp_longclock(lnow, append->nexttime) >= 0) > > assuming that nexttime was set correctly, and lnow is correct, too, > > and further assuming your clock_t is only 32 bit, > > longclock_t is defined as unsigned long long, > > and that thing becomes: > > > > if ((unsigned long long)(lnow) >= (unsigned long long)(append->nexttime)) > > > > which exactly does _NOT_ care for wrap around :( > > > > > > example: > > say, you start with a _large_ lnow (e.g. the equivalent of "-15 > > But you can't start with large lnow. lnow is 64-bit and you can't > get that far into the future. Hm. Right. Then maybe something else is wrong, like some wrong typecast? int i = -300000; unsigned long long l_wrong = i; unsigned long long l_right = (unsigned long long)(unsigned int)i; l_wrong is now "very far" into the future, and my patch would fix the comparison of that. whereas l_right is just below 2<<32, and will compare fine in 64 bit wide unsigned long long, with the existing code. Simon: can you help to track this down? Which exact "platform" is this on, heartbeat version, configure and compiler flags... You could also try to start this in a VM, and try to reproduce? Or shall we just ignore this for now? -- : Lars Ellenberg : LINBIT | Your Way to High Availability : DRBD/HA support and consulting http://www.linbit.com DRBD(r) and LINBIT(r) are registered trademarks of LINBIT, Austria. _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
