Date: Thu, 22 Feb 2001 20:47:39 -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.010222204739.jhb@FreeBSD.org> In-Reply-To: <Pine.BSF.4.33.0102222246530.16616-100000@mobile.hub.org>
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On 23-Feb-01 The Hermit Hacker wrote: > On Thu, 22 Feb 2001, John Baldwin wrote: > >> >> On 22-Feb-01 The Hermit Hacker wrote: >> > >> > Okay, I have to pick up a NULL modem cable tomorrow and dive into this ... >> > finally ... >> > >> > The various KTR_ that you mention below, these are kernel settings that I >> > compile into the kernel? >> >> Yes. You want this: >> >> options KTR >> options KTR_EXTEND >> options KTR_COMPILE=0x1208 > > okay, just so that I understand ... I compile my kernel with these > options, and then run the two sysctl commands you list below? the > KTR_COMPILE arg looks similar to the ktr_mask one below, which is why I'm > confirming ... Yes. KTR_COMPILE controls what KTR tracepoints are actually compiled into the kernel. The ktr_mask sysctl controls a runtime mask that lets you choose which of the compiled in masks you want to enable. I have manpages for this stuff, but they are waiting for doc guys to review them. >> The mtx_quiet.patch is old and won't apply to current now I'm afraid. >> >> > On Tue, 2 Jan 2001, John Baldwin wrote: >> > >> >> >> >> 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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