Subject : Reproducable hang with 2.6.24-rc2 using oprofile Submitter : Jan Kara <jack@suse.cz> References : http://lkml.org/lkml/2007/11/13/225
I've bisected a bit and the following commit is the one causing it: commit 574a60421c8ea5383a54ebee1f37fa871d00e1b9 Author: Jan Blunck <jblunck@suse.de> Date: Fri Oct 19 20:35:03 2007 +0200 i386: make callgraph use dump_trace() on i386/x86_64
does 2.6.24-rc3 fix it? It has an oprofile fix: | commit df9d177aa28d50e64bae6fbd6b263833079e3571 | Author: Philippe Elie <phil.el@wanadoo.fr> | Date: Wed Nov 14 16:58:48 2007 -0800 | | oProfile: oops when profile_pc() returns ~0LU if that does not help then we'll revert the commit you bisected so excellently.
It helps! The kernel does not hang any more and I'm even able to get some numbers from oprofile :). Thanks. I just wonder how come I didn't see any message on the console - I used standard VGA console to maximize the possibility I'd see something before hang...
profiling might crash in places where the crash handler itself profiles too, etc. - resulting in a hard hang. nmi_watchdog=2 (or =1) could perhaps have gotten a backtrace.