running 5.1-RELEASE with no procfs mounted (lockups?)
Pawel Jakub Dawidek
nick at garage.freebsd.pl
Fri Jul 18 11:21:27 PDT 2003
On Fri, Jul 18, 2003 at 01:45:34AM -0700, Terry Lambert wrote:
+> > +> truss Relies on the event model of procfs; there have been some
+> > +> initial patches and discussion of migrating truss to ptrace() but
+> > +> I don't think we have anything very usable yet. I'd be happy to
+> > +> be corrected on this. :-)
+> >
+> > Hmm, why to change this behaviour? Is there any functionality that
+> > ktrace(1) doesn't provide?
+>
+> It can interactively run in another window, giving you realtime
+> updates on what's happening up to the point of a kernel crash.
+> With ktrace, you are relatively screwed.
Hmm, you're talking about:
# ktrace -p <PID>
# kdump -l
?
+> Another good example is that it dump out information that ktrace
+> can't, because of where it synchronizes. Some people recently
+> have been seeing "EAGAIN" when they haven't expected it, with
+> the process exiting immediately after that, with no real clue
+> as to where in the code it's happening (e.g. which system call);
+> truss will show this, if run in another terminal window, but
+> ktrace will not (yes, I know it should; it doesn't. If you can't
+> reconcile this with how you think ktrace should work, then fix it).
Note, that I'm not for removing truss(1). I'm only saying that in most
cases ktrace(1) is sufficient. You can always mount procfs in those
special situations.
--
Pawel Jakub Dawidek pawel at dawidek.net
UNIX Systems Programmer/Administrator http://garage.freebsd.pl
Am I Evil? Yes, I Am! http://cerber.sourceforge.net
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