Re: [Qemu-devel] [PATCH for-next v3 2/5] tmp105: Add debug output

[Paolo Bonzini]

Il 15/02/2013 14:14, Alexander Graf ha scritto:
>> > 
>> > I'm assuming that changes to ppc logging go through ppc-next, changes to
>> > sparc code go through Blue etc. All those potentially conflict since
>> > they're adding to the bottom of the same text file, thus coordination.
>> > It's a long-standing criticism of our centralistic tracing
>> > infrastructure compared to the totally decentral and inhomogeneous
>> > DPRINTFs and what-nots on the other hand.

I rarely found conflicts in trace-events, but in this case you would
indeed have them.  Trivial to solve, however.

> In parallel to the completely disastrous user experience when using trace 
> points.

What exactly is disastrous?  We could have improvements (such as having
multiple trace backends compiled in an executable, e.g. simple+stderr,
or having gdb magic to enable/disable them from command breakpoints).
But in general, I find trace points to be quite easy to use, and
unintrusive enough to let you debug performance problems.

Paolo