Re: [PATCH] Linux Kernel GDB tracepoint module 2011-02-05

[Tom Tromey <tromey@redhat.com>]

>>>>> ">" == Hui Zhu <teawater@gmail.com> writes:

>> We have trouble for this printf is GDB is still not accept the patch
>> that make tracepoint support printf, So if you want use it, you need
>> patch the patch in
>> http://sourceware.org/ml/gdb-patches/2011-02/msg00063.html and build
>> your GDB with yourself.

Thanks, I think this example was helpful.

>> Sometimes, GDB will output some value like:
>> inode has been optimized out of existence.
>> res has been optimized out of existence.
>> That is because value of inode and res is optimized. Linux Kernel is
>> built with -O2 so you will get this trouble sometimes. If you do not
>> care about the speed when you debug the Kernel, you can use the patch
>> for Linux Kernel in

I am curious to know what version of GCC you are using.  IME, the VTA
patches really helped with this problem a lot -- though not completely.
If you are not using a VTA-enabled GCC, you should.  And if you are, I
think bug reports about values that are still optimized out would be
useful.

Tom