Re: [PATCH v1] arch/x86: port I/O tracing on x86

[Dan Raymond]

> No, very much no.
> 
> This sticks tracing in the very rawest of raw output paths.

That's the point.  Tracing is a low level debug tool that can be
used to debug the kernel itself.  If you don't trace all port I/O
then you are bound to miss something important while debugging.

> This means I can no longer use early_console->write() to print to my
> early_serial_console.

Why not?  Did you try it?

> That is the one and only fully reliably output path we have. You're not
> sticking tracing in it.

Keep in mind that tracing is optional.  It can be turned off using
CONFIG_TRACEPOINTS.