On Tue, 11 Dec 2018 15:09:26 +0100
Petr Mladek <pmladek@xxxxxxxx> wrote:
> > We have liburcu already, which is good. The main sticking points are:
> >
> > - printk has started adding a lot of %pX enhancements which printf
> > obviously doesn't know about.
>
> I wonder how big problem it is and if it is worth using another
> approach.
No, please do not change the %pX approach.
>
> An alternative would be to replace them with helper functions
> the would produce the same string. The meaning would be easier
> to understand. But concatenating with the surrounding text
> would be less elegant. People might start using pr_cont()
> that is problematic (mixed lines).
>
> Also the %pX formats are mostly used to print context of some
> structures. Even the helper functions would need some maintenance
> to keep them compatible.
>
> BTW: The printk() feature has been introduced 10 years ago by
> the commit 4d8a743cdd2690c0bc8 ("vsprintf: add infrastructure
> support for extended '%p' specifiers").
trace-cmd and perf know about most of the %pX data and how to read it.
Perhaps we can extend the libtraceevent library to export a generic way
to read data from printk() output for other tools to use.
-- Steve
