2009/12/14 Jason Wessel <[email protected]>: > Jiaqing Du wrote: >> 2009/12/14 Jason Wessel <[email protected]>: >> >>> Jiaqing Du wrote: >>> >>>> Hi List, >>>> >>>> I am trying to use kgdb to debug some kernel modules (mainly for >>>> oprofile and kvm). I had some weird problems. For example, break >>>> points do not work and the target kernel hangs on a breakpoint to a >>>> interrupt handler. Then I compiled the kernel with kgdbts. At least >>>> for stable release of 2.6.31.7, it did not pass the testing (with >>>> kgdbts=V2). I'm wondering if every stable release really passes the >>>> kgdbts testing? Or I'm doing something wrong? >>>> >>>> >>>> >>> There was some instability in kgdb with respect to the x86 architecture >>> and single stepping on a multi-cpu system. These fixes were merged to >>> the 2.6.33 development stream last week. Of course in the 2.6.33 >>> kernel the HW breakpoints are presently broken. >>> >>> I had not yet made a set of patches for the 2.6.32 kernel, but the >>> 2.6.33 patch set would certainly apply cleanly. >>> >>> If you are using kvm, I would recommend not using kgdb, and instead >>> using the kvm backend debugger. >>> >> >> What is the kvm backend debugger? After searching KVM mailing list, I >> could not find anything. >> >> > > Please look up in the documentation for kvm's user space. > > -S freeze CPU at startup (use 'c' to start execution) > -gdb dev wait for gdb connection on 'dev' > -s shorthand for -gdb tcp::1234 > > That creates a gdb serial communications channel between the kvm > instance and a debugger, not unlike using kgdb. > > Jason. >
Actually I plan to use kgdb to debug the KVM kernel module, not the guest running inside it. I want to check under which point an NMI happens. Do you think kgdb can help me in this case? Which branch or tag of linux-2.6-kgdb.git should I use? Thanks, Jiaqing ------------------------------------------------------------------------------ Return on Information: Google Enterprise Search pays you back Get the facts. http://p.sf.net/sfu/google-dev2dev _______________________________________________ Kgdb-bugreport mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport
