On 23-1-2013 11:22, Michael Haberler wrote: > Am 23.01.2013 um 10:12 schrieb David Armstrong: > >>>>> On 21-1-2013 22:20, Michael Haberler wrote: >>>>>> I assume Bas will give the postmortem shortly - he nailed the issue; the >>>>>> RTC boot timewarp makes for a lost DHCP lease midflight and NFS >>>>>> freezing, making it look like a kernel hang. >>>>>> >> ok i dont mind being shot down in flames , but would adding a RTC module >> be a answer >> for example :-) >> >> http://www.ebay.co.uk/itm/New-Arduino-I2C-RTC-DS1307-AT24C32-Real-Time-Clock-Module-For-AVR-ARM-PIC-/170794819927?pt=UK_BOI_Electrical_Comp >> >> although i must admit it ends up having all sorts of a rats nest for now >> , and if theirs no other answer >> and we end up making an interface for the Beagle the it could be more >> permamant >> >> i mention the above rtc only for the fact that i have one laying around > > I'd think that'd be way overkill, it looks like one of this PC-architecture > based assumptions violated which can be relied upon to have a battery-backed > RTC Agreed, IMHO only stand-alone systems without networking would benefit from a hardware solution. And these systems aren't affected by the freeze... > > now that we know what is at the core of the problem, all we need is a robust > way of handling it, i.e. to assure that a lease doesnt expire underneath > midflight > > there are several ways to 'fix' it for now, with varying degrees of > sturdyness and elegance > > - the most robust way for now is use a static IP address assignment in > /etc/network/interfaces (that's the 'given a big enough hammer...' method, > although your hammer would be much bigger ;) Watch your fingers with that big hammer! > - I installed ntp and this seems to time-warp the RTC right away, but it > assumes connectivity to an NTP server and making a successful boot > conditional on NTP is less than bright and an excellent source of support > problems I still don't understand why this would work. The DHCP lease has to be obtained before the network connection comes 'up', and thus before NTP can do the time warp. Or is NTP able to set the system time before the connection is up, via some kind of broadcast? > - renewing the dhcp lease during boot after setting the time might be an > option I think this is the way to go. The dhclient I'm running doesn't seem to release the lease if it's killed. So probably a kill client, remove lease file, start client again will work. As soon as I've done a lot of other things in my queue I'll revert my configuration and try this method. > - I'm working on an updated BB xenomai kernel which seems the 'fixrtc' option > wired in as the bootlog says: > [ 1.598631] omap_rtc am33xx-rtc: setting system clock to 2013-01-23 > 10:07:21 UTC (1358935641) > without me adding 'fixrtc' to the boot command line - I think this is a > dubious method though since all it needs to fail miserably is to power off > the BB long enough True, but if the power is off long enough the system will freeze. So after a curse you'll reset the system and then it'll work ; ) > > btw Xenomai per se doesnt need RTC support, so it's a plain Linux issue. > > summary: make it work now; make it work elegantly later. Dont bother > squashing rather trivial bugs with extra hardware. > > - Michael > > ps: on the new kernel - working with 'TI official sources' doesnt necessarily > translate into 'that's been through some really painstaking quality control' > - there are all sorts of issues, like code which has syntax errors derived > from a copy & paste and obviously nobody even tried to compile the result; or > options introduced which make the build break if the option isnt selected and > the like. No comment.
-- Bas > > Suddenly our buildbot looks like a stunning quality assurance tool on the > forefront of software engineering ;) > > > > > > > > > > ------------------------------------------------------------------------------ > Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, > MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current > with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft > MVPs and experts. ON SALE this month only -- learn more at: > http://p.sf.net/sfu/learnnow-d2d > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers ------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
