Date: Tue, 02 Jan 2001 11:36:20 -0800 (PST) From: John Baldwin <jhb@FreeBSD.org> To: The Hermit Hacker <scrappy@hub.org> Cc: freebsd-current@FreeBSD.org Subject: RE: System hangs with -current ... Message-ID: <XFMail.010102113620.jhb@FreeBSD.org> In-Reply-To: <Pine.BSF.4.31.0101021021360.672-100000@thelab.hub.org>
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On 02-Jan-01 The Hermit Hacker wrote: > > Over the past several months, as others have reported, I've been getting > system hangs using 5.0-CURRENT w/ SMP ... I've got DDB enabled, but > ctl-alt-esc doesn't break me to the debugger ... > > I'm not complaining about the hangs, if I was overly concerned, I'd run > -STABLE, but I'm wondering how one goes about providing debug information > on them other then through DDB? Not easily. :( If you can make the problem easily repeatable, then you can try turning on KTR in your kernel (see NOTES, you will need KTR_EXTEND), setting up a serial console that you log the output of, create a shell script that runs the following commands: #!/bin/sh # Turn on KTR_INTR, KTR_PROC, and KTR_LOCK sysctl -w debug.ktr_mask=0x1208 sysctl -w debug.ktr_verbose=2 run_magic_command_that_hangs_my_machine and run the script. You probably want to run it over a tty or remote login so tthat the serial console output is just the logging (warning, it will be very verbose!). Also, you probably want to use http://www.FreeBSD.org/~jhb/patches/mtx_quiet.patch to shut up most of the irrelevant and cluttery mutex trace messages. Note that having this much logging on will probably slow the machine to a crawl as well, so you may have to just start this up and go off and do something else until it hangs. :-/ Another alternative is to rig up a NMI debouncer and use it to break into the debugger. Then you can start poking around to see who owns sched_lock, etc. > Thanks ... -- John Baldwin <jhb@FreeBSD.org> -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.baldwin.cx/~john/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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