Date: Sat, 22 Apr 2006 15:05:10 -0400 From: Erin E Conn <econn@nc.rr.com> To: "R. B. Riddick" <arne_woerner@yahoo.com> Cc: freebsd-multimedia@freebsd.org Subject: Re: Rebooting problems with /dev/cxm0 Message-ID: <444A7E66.8010509@nc.rr.com> In-Reply-To: <20060422065502.75770.qmail@web30315.mail.mud.yahoo.com> References: <20060422065502.75770.qmail@web30315.mail.mud.yahoo.com>
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R. B. Riddick wrote: > --- Erin E Conn <econn@nc.rr.com> wrote: > Maybe your hardware configuration is more stable... I did not try it again (I > have more than 64 days of uptime now... (-:), but I am still quite sure that > this "dd" command with a block size of 1 byte crashed the box almost > immediately. > > Did you select a channel before doing the test? Yes, in fact the dd command fails complaining that the device has not been configured if I do not set a channel first. >>> Furthermore the power saving features should be disabled in >>> my box, I think (I did not test it thoroughly - at least whenever >>> the power saving started the box crashed, when I read from >>> /dev/cxm0 at that time)... :-) >>> > Do you still have the problem with spontaneous crashes/reboots after some > minutes? Have you checked your BIOS settings about power saving stuff? It crashes before any of my power saving features have time to kick in. >>> Since I split the reading from cxm0 and transfering to hard disc (partially >>> via network) in two processes, that use 8 or about 8 buffers (each 2MB >>> or about 2MB), I do not have this problem (61 days uptime... :-)) And >>> each day at least 3h of reading from /dev/cxm0 - at most days much >>> more: 6h or so). >>> > I wrote a little C program, that uses "fork" (for creating another process) and > "mmap" (for getting shared memory for inter process communication). But most > likely this is not needed in your case, since there is no big latency, when u > write to ur local harddisc. > > I could send u the two C programs (one for gathering+marshalling and one for > demarshalling. Thanks, those might be helpful. >>> Maybe that helps (e. g.: just try to do "dd if=/dev/cxm0 of=/dev/null bs=1m >>> count=1000"). >> How are you splitting the reading into 2 processes, and are >> you able to watch live TV using this method? >> > And for how long could you do this test? I mean: If it crashed every 2-5 > minutes with "cat", when does it crash, when you use "dd"? > Interestingly, using dd, the computer did not crash, but the X server dumped core and restarted, which killed the dd process since I was running it in an xterm. Trying it from the console to see if that makes a difference. It crashed after about the same amount of time as cat did, using a blocksize of 1m. -Erin
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